Titus Flavius Domitianus (24 October 51 – 18 September 96), commonly known as Domitian, was Roman Emperor from 81 to 96. Domitian was the third and last emperor of the Flavian dynasty.

Domitian's youth and early career were largely spent in the shadow of his brother Titus, who gained military renown during the First Jewish - Roman War. This situation continued under the rule of his father Vespasian, who became emperor in 69 following the civil war known as theYear of the Four Emperors. While Titus effectually reigned as co-emperor with his father, Domitian was left with honours but no responsibilities. Vespasian died in 79 and was succeeded by Titus, whose own reign came to an unexpected end when he was struck by a fatal illness in 81. The following day Domitian was declared emperor by the Praetorian Guard, commencing a reign which lasted fifteen years - longer than any man who had ruled since Tiberius. As emperor, Domitian strengthened the economy by revaluing the Roman coinage, expanded the border defenses of the empire, and initiated a massive building program to restore the damaged city of Rome. Significant wars were fought in Britain, where his general Agricola attempted to conquer Scotland, and in Dacia, where Domitian was unable to procure a decisive victory against king Decebalus. Domitian's government exhibited totalitarian characteristics; he saw himself as the new Augustus, an enlightened despot destined to guide the Roman Empire into a new era of brilliance. Religious, military, and cultural propaganda fostered a cult of personality, and by nominating himself perpetual censor, he sought to control public and private morals. As a consequence, Domitian was popular with the people and army but considered a tyrant by members of the Roman Senate. Domitian's reign came to an end in 96 when he was assassinated by court officials. The same day he was succeeded by his advisor Nerva. After his death, Domitian's memory was condemned to oblivion by the Roman Senate, while senatorial authors such as Tacitus, Pliny the Younger and Suetonius published histories propagating the view of Domitian as a cruel and paranoid tyrant. Modern history has rejected these views, instead characterising Domitian as a ruthless but efficient autocrat, whose cultural, economic and political program provided the foundation of the peaceful second century.

Domitian was born in Rome on 24 October 51, the youngest son of Titus Flavius Vespasianus — commonly known as Vespasian — and Flavia Domitilla Major. He had an older sister, Domitilla the Younger, and brother, also named Titus Flavius Vespasianus.

Decades of civil war during the 1st century BC had contributed greatly to the demise of the old aristocracy of Rome, which was gradually replaced in prominence by a new Italian nobility during the early part of the 1st century. One such family was the Flavians, or gens Flavia, which rose from relative obscurity to prominence in just four generations, acquiring wealth and status under the emperors of the Julio-Claudian dynasty. Domitian's great-grandfather, Titus Flavius Petro, had served as a centurion under Pompey during Caesar's civil war. His military career ended in disgrace when he fled the battlefield at the Battle of Pharsalus in 48 BC. Nevertheless, Petro managed to improve his status by marrying the extremely wealthy Tertulla, whose fortune guaranteed the upwards mobility of Petro's son Titus Flavius Sabinus I, Domitian's grandfather. Sabinus himself amassed further wealth and possible equestrian status through his services as tax collector in Asia and banker in Helvetia (modern Switzerland). By marrying Vespasia Polla he allied himself to the more prestigious patrician gens Vespasia, ensuring the elevation of his sons Titus Flavius Sabinus II and Vespasian to the senatorial rank.

The political career of Vespasian included the offices of quaestor, aedile and praetor, and culminated with a consulship in 51, the year Domitian was born. As a military commander, he gained early renown by participating in the Roman invasion of Britain in 43. Nevertheless, ancient sources allege poverty for the Flavian family at the time of Domitian's upbringing, even claiming Vespasian had fallen into disrepute under the emperors Caligula (37 – 41) and Nero (54 – 68). Modern history has refuted these claims, suggesting these stories were later circulated under Flavian rule as part of a propaganda campaign to diminish success under the less reputable Emperors of the Julio-Claudian dynasty, and maximize achievements under Emperor Claudius (41 – 54) and his son Britannicus. By all appearances, imperial favour for the Flavians was high throughout the 40s and 60s. While Titus received a court education in the company of Britannicus, Vespasian pursued a successful political and military career. Following a prolonged period of retirement during the 50s, he returned to public office under Nero, serving as proconsul of the Africa province in 63, and accompanying the emperor during an official tour of Greece in 66. The same year the Jews of the Judaea province revolted against the Roman Empire, in what is now known as the First Jewish - Roman War. Vespasian was assigned to lead the Roman army against the insurgents, with Titus — who had completed his military education by this time — in charge of a legion.

By 66, Domitian's mother and sister had long died, while his father and brother were continuously active in the Roman military, commanding armies in Germania and Judaea. For Domitian, this meant that a significant part of his adolescence was spent in the absence of his near relatives. During the Jewish - Roman wars, he was likely taken under the care of his uncle Titus Flavius Sabinus II, at the time serving as city prefect of Rome; or possibly even Marcus Cocceius Nerva, a loyal friend of the Flavians and the future successor to Domitian.

He received the education of a young man of the privileged senatorial class, studying rhetoric and literature. In his biography in the Lives of the Twelve Caesars, Suetonius attests to Domitian's ability to quote the important poets and writers such as Homer or Virgil on appropriate occasions, and describes him as a learned and educated adolescent, with elegant conversation. Among his first published works were poetry, as well as writings on law and administration. Unlike his brother Titus, Domitian was not educated at court. Whether he received formal military training is not recorded, but according to Suetonius, he displayed considerable marksmanship with the bow and arrow. A detailed description of Domitian's appearance and character is provided by Suetonius, who devotes a substantial part of his biography to his personality.

He was tall of stature, with a modest expression and a high colour. His eyes were large, but his sight was somewhat dim. He was handsome and graceful too, especially when a young man, and indeed in his whole body with the exception of his feet, the toes of which were somewhat cramped. In later life he had the further disfigurement of baldness, a protruding belly, and spindling legs, though the latter had become thin from a long illness.

Suetonius, De Vita Caesarum, "Life of Domitian"

Domitian was allegedly extremely sensitive regarding his baldness, which he disguised in later life by wearing wigs. According to Suetonius, he even wrote a book on the subject of hair care. With regard to Domitian's personality, however, the account of Suetonius alternates sharply between portraying Domitian as the emperor tyrant, a man both physically and intellectually lazy, and the intelligent, refined personality drawn elsewhere. Brian Jones concludes in The Emperor Domitian that assessing the true nature of Domitian's personality is inherently complicated by the bias of the surviving sources. Common threads nonetheless emerge from the available evidence. He appears to have lacked the natural charisma of his brother and father. He was prone to suspicion, displayed an odd, sometimes self-deprecating sense of humour, and often communicated in cryptic ways. This ambiguity of character was further exacerbated by his remoteness, and as he grew older, he increasingly displayed a preference for solitude, which may have stemmed from his isolated upbringing. Indeed, by the age of eighteen nearly all of his closest relatives had died by war or disease. Having spent the greater part of his early life in the twilight of Nero's reign, his formative years would have been strongly influenced by the political turmoil of the 60s, culminating with the civil war of 69, which brought his family to power.

On 9 June 68, amidst growing opposition of the Senate and the army, Nero committed suicide, and with him the Julio-Claudian dynasty came to an end. Chaos ensued, leading to a year of brutal civil war known as the Year of the Four Emperors, during which the four most influential generals in the Roman Empire — Galba, Otho, Vitellius and Vespasian — successively vied for imperial power. News of Nero's death reached Vespasian as he was preparing to besiege the city of Jerusalem. Almost simultaneously the Senate had declared Galba, then governor of Hispania Tarraconensis (modern Spain), as Emperor of Rome. Rather than continue his campaign, Vespasian decided to await further orders and send Titus to greet the new Emperor. Before reaching Italy however, Titus learnt that Galba had been murdered and replaced by Otho, the governor of Lusitania (modern Portugal). At the same time Vitellius and his armies in Germania had risen in revolt, and prepared to march on Rome, intent on overthrowing Otho. Not wanting to risk being taken hostage by one side or the other, Titus abandoned the journey to Rome and rejoined his father in Judaea.

Otho and Vitellius realised the potential threat posed by the Flavian faction. With four legions at his disposal, Vespasian commanded a strength of nearly 80,000 soldiers. His position in Judaea further granted him the advantage of being nearest to the vital province of Egypt, which controlled the grain supply to Rome. His brother Titus Flavius Sabinus II, as city prefect, commanded the entire city garrison of Rome. Tensions among the Flavian troops ran high, but so long as either Galba or Otho remained in power, Vespasian refused to take action. When Otho was defeated by Vitellius at the First Battle of Bedriacum however, the armies in Judaea and Egypt took matters into their own hands and declared Vespasian emperor on 1 July 69. Vespasian accepted, and entered an alliance with Gaius Licinius Mucianus, the governor of Syria, against Vitellius. A strong force drawn from the Judaean and Syrian legions marched on Rome under the command of Mucianus, while Vespasian himself travelled to Alexandria, leaving Titus in charge of ending the Jewish rebellion.

In Rome meanwhile, Domitian was placed under house arrest by Vitellius, as a safeguard against future Flavian aggression. Support for the old emperor was waning however, as more legions throughout the empire pledged their allegiance to Vespasian. On 24 October 69 the forces of Vitellius and Vespasian clashed at the Second Battle of Bedriacum, which ended in a crushing defeat for the armies of Vitellius. In despair, he attempted to negotiate a surrender. Terms of peace, including a voluntary abdication, were agreed upon with Titus Flavius Sabinus II, but the soldiers of the Praetorian Guard — the imperial bodyguard — considered such a resignation disgraceful, and prevented Vitellius from carrying out the treaty. On the morning of 18 December, the emperor appeared to deposit the imperial insignia at the Temple of Concord, but at the last minute retraced his steps to the imperial palace. In the confusion, the leading men of the state gathered at Sabinus' house, proclaiming Vespasian Emperor, but the multitude dispersed when Vitellian cohorts clashed with the armed escort of Sabinus, who was forced to retreat to the Capitoline Hill. During the night, he was joined by his relatives, including Domitian. The armies of Mucianus were nearing Rome, but the besieged Flavian party did not hold out for longer than a day. On 19 December, Vitellianists burst onto the Capitol, and in the resulting skirmish, Sabinus was captured and executed. Domitian himself managed to escape by disguising himself as a worshipper of Isis, and spent the night in safety with one of his father's supporters. By the afternoon of 20 December Vitellius was dead, his armies having been defeated by the Flavian legions. With nothing more to be feared from the enemy, Domitian came forward to meet the invading forces; he was universally saluted by the title of Caesar, and the mass of troops conducted him to his father's house. The following day, 21 December, the Senate proclaimed Vespasian emperor of the Roman Empire.

Although the war had officially ended, a state of anarchy and lawlessness pervaded in the first days following the demise of Vitellius. Order was properly restored by Mucianus in early 70, but Vespasian did not return to Rome until September of that year. In the meantime Domitian acted as the representative of the Flavian family in the Roman Senate. In addition to receiving the title of Caesar, he was appointed praetor with consular power. Domitian's authority was merely nominal however, foreshadowing what was to be his role for at least ten more years. By all accounts, Mucianus held the real power in Vespasian's absence, and he was careful to ensure that Domitian, still only eighteen years old, did not overstep the boundaries of his function. The ancient historian Tacitus describes Domitian's first speech in the Senate as brief and measured, at the same time noting his ability to elude awkward questions. Strict control was also maintained over the young Caesar's entourage, promoting away influential generals such as Arrius Varus, Praetorian prefect, and Antonius Primus, who had led the Flavian forces at Bedriacum, and replacing them by more reliable men such as Arrecinus Clemens.

Equally curtailed by Mucianus were Domitian's military ambitions. The civil war of 69 had severely destabilized the provinces, leading to several local uprisings such as the Batavian revolt in Gaul. Batavian auxiliaries of the Rhine legions, led by Gaius Julius Civilis, had rebelled with the aid of a faction of Treveri under the command of Julius Classicus. Seven legions were sent from Rome, led by Vespasian's brother-in-law Quintus Petillius Cerialis. Although the revolt was quickly suppressed, exaggerated reports of disaster prompted Mucianus to depart the capital with reinforcements of his own. Domitian eagerly sought the opportunity to attain military glory, and joined the other officers with the intention of commanding a legion of his own. According to Tacitus, Mucianus was not keen on this prospect, but he considered Domitian a liability in any capacity that was entrusted to him and therefore preferred to keep him close at hand rather than in Rome. When news arrived of Cerialis' victory over Civilis, Mucianus tactfully dissuaded Domitian from pursuing further military endeavours. Domitian then wrote to Cerialis personally, suggesting he hand over command of his army but, once again, he was snubbed. With the return of Vespasian in late September, his political role was rendered all but obsolete, and Domitian withdrew from government devoting his time to arts and literature.

Where his political and military career had ended in disappointment, Domitian's private affairs were more successful in 70. Vespasian attempted to arrange a dynastic marriage between his youngest son and the daughter of Titus, Julia Flavia, but Domitian was adamant in his love for Domitia Longina, going so far as to persuade her husband, Lucius Aelius Lamia, to divorce her so that Domitian could marry her himself. Despite its initial recklessness, the alliance was very prestigious for both families. Domitia Longina was the younger daughter of Gnaeus Domitius Corbulo, a respected general and honoured politician. Following the failed Pisonian conspiracy against Nero in 65, he had been forced to commit suicide. The new marriage not only re-established ties to senatorial opposition, but also served the broader Flavian propaganda of the time, which sought to diminish Vespasian's political success under Nero. Instead connections to Claudius and Britannicus were emphasised, and Nero's victims, or those otherwise disadvantaged by him, rehabilitated. In 73, Domitia and Domitian's only attested son was born. It is not known what the boy's name was, but he died in childhood sometime between 77 and 81. Shortly following his accession as Emperor, Domitian bestowed the honorific title of Augusta upon Domitia, while their son was deified, appearing as such on the reverse of coin types from this period. Nevertheless, the marriage appears to have faced a significant crisis in 83. For reasons unknown, Domitian briefly exiled Domitia, and then soon recalled her, either out of love or due to rumours that he was carrying on a relationship with his niece Julia Flavia. Jones argues that most likely he did so for her failure to produce an heir. By 84, Domitia had returned to the palace, where she lived for the remainder of Domitian's reign without incident. Little is known of Domitia's activities as Empress, or how much influence she wielded in Domitian's government, but it seems her role was limited. From Suetonius, we know that she at least accompanied the Emperor to the amphitheatre, while the Jewish writer Josephus speaks of benefits he received from her. It is not known whether Domitian had other children, but he did not marry again. Despite allegations by Roman sources of adultery and divorce, the marriage appears to have been happy.

Prior to becoming Emperor, Domitian's role in the Flavian government was largely ceremonial. In June of 71, Titus returned triumphant from the war in Judaea. Ultimately, the rebellion had claimed the lives of over 1 million people, a majority of which were Jewish. The city and temple of Jerusalem were completely destroyed, its most valuable treasures carried off by the Roman army, and nearly 100,000 people were captured and enslaved. For his victory, the Senate awarded Titus a Roman triumph. On the day of the festivities, the Flavian family rode into the capital, preceded by a lavish parade which displayed the spoils of the war. The family procession was headed by Vespasian and Titus, while Domitian, riding a magnificent white horse, followed with the remaining Flavian relatives. Leaders of the Jewish resistance were executed in the Forum Romanum, after which the procession closed with religious sacrifices at the Temple of Jupiter. A triumphal arch, the Arch of Titus, was erected at the south-east entrance to the Forum to commemorate the successful end of the war.

Yet the return of Titus further highlighted the comparative insignificance of Domitian, both militarily and politically. As the eldest and most experienced of Vespasian's sons, Titus shared tribunician power with his father, received seven consulships, the censorship, and was given command of the Praetorian Guard; powers which left no doubt he was the designated heir to the Empire. As a second son, Domitian held honorary titles, such as Caesar or Princeps Iuventutis, and several priesthoods, including those of augur, pontifex, frater arvalis, magister frater arvalium, and sacerdos collegiorum omnium, but no office with imperium. He held six consulships during Vespasian's reign but only one of these, in 73, was an ordinary consulship. The other five were less prestigious suffect consulships, which he held in 71, 75, 76, 77 and 79 respectively, usually replacing his father or brother in mid-January. While ceremonial, these offices no doubt gained Domitian valuable experience in the Roman Senate, and may have contributed to his later reservations about its relevance. Under Vespasian and Titus, non-Flavians were virtually excluded from the important public offices. Mucianus himself all but disappeared from historical records during this time, and it is believed he died sometime between 75 and 77. Real power was unmistakably concentrated in the hands of the Flavian faction; the weakened Senate only maintained the facade of democracy.

Because Titus effectively acted as co-emperor with his father, no abrupt change in Flavian policy occurred when Vespasian died on 23 June 79. Titus assured Domitian that full partnership in the government would soon be his, but neither tribunician power nor imperium of any kind was conferred upon him during Titus' brief reign. Understandably, the new emperor was not eager to alter this arrangement: he would have expected to rule for at least another twenty or thirty years, and urgent attention was required to address the multitude of disasters which struck during 79 and 80. On 24 August 79, Mount Vesuvius erupted, burying the surrounding cities of Pompeii and Herculaneum under metres of ash and lava; the following year, a fire broke out in Rome which lasted three days and which destroyed a number of important public buildings. Consequently, Titus spent much of his reign coordinating relief efforts and restoring damaged property. On 13 September 81 after barely two years in office, he unexpectedly died of fever during a trip to the Sabine territories.

Ancient authors have implicated Domitian in the death of his brother, either by directly accusing him of murder, or implying he left the ailing Titus for dead, even alleging that during his lifetime, Domitian was openly plotting against his brother. It is difficult to assess the factual veracity of these statements given the known bias of the surviving sources. Brotherly affection was likely at a minimum, but this was hardly surprising, considering that Domitian had barely seen Titus after the age of seven. Whatever the nature of their relationship, Domitian seems to have displayed little sympathy when his brother lay dying, instead making for the Praetorian camp where he was proclaimed emperor. The following day, 14 September, the Senate confirmed Domitian's powers, granting tribunician power, the office of Pontifex Maximus, and the titles of Augustus, and Pater Patriae.

As Emperor, Domitian quickly dispensed with the republican facade his father and brother had maintained during their reign. By moving the centre of government (more or less formally) to the imperial court, Domitian openly rendered the Senate's powers obsolete. In his view, the Roman Empire was to be governed as a divine monarchy with himself as the benevolent despot at its head. In addition to exercising absolute political power, Domitian believed the emperor's role encompassed every aspect of daily life, guiding the Roman people as a cultural and moral authority. To usher in the new era, he embarked on ambitious economic, military and cultural programs with the intention of restoring the Empire to the splendour it had seen under the emperor Augustus.

Despite these grand designs Domitian was determined to govern the Empire conscientiously and scrupulously. He became personally involved in all branches of the administration: edicts were issued governing the smallest details of everyday life and law, while taxation and public morals were rigidly enforced. According to Suetonius, the imperial bureaucracy never ran more efficiently than under Domitian, whose exacting standards and suspicious nature maintained historically low corruption among provincial governors and elected officials. Although he made no pretence regarding the significance of the Senate under his absolute rule, those senators he deemed unworthy were expelled from the Senate, and in the distribution of public offices he rarely favoured family members; a policy which stood in contrast to the nepotism practiced by Vespasian and Titus. Above all, however, Domitian valued loyalty and malleability in those he assigned to strategic posts, qualities he found more often in men of the equestrian order than in members of the Senate or his own family, whom he regarded with suspicion, and promptly removed from office if they disagreed with imperial policy.

The reality of Domitian's autocracy was further highlighted by the fact that, more than any emperor since Tiberius, he spent significant periods of time away from the capital. Although the Senate's power had been in decline since the fall of the Republic, under Domitian the seat of power was no longer even in Rome, but rather wherever the Emperor was. Until the completion of the Flavian Palace on the Palatine Hill, the imperial court was situated at Alba or Circeo, and sometimes even farther afield. Domitian toured the European provinces extensively, and spent at least three years of his reign in Germania and Illyricum, conducting military campaigns on the frontiers of the Empire.

Domitian's tendency towards micromanagement was nowhere more evident than in his financial policy. The question of whether Domitian left the Roman Empire in debt or with a surplus at the time of his death has been fiercely debated. However the evidence points to a balanced economy for the greater part of Domitian's reign. Upon his accession he revalued the Roman currency to the standard of Augustus, increasing the silver content of the denarius by 12%. An imminent crisis in 85 forced a devaluation to the Neronian standard of 65, but this was still higher than the level which Vespasian and Titus had maintained during their reign. Domitian's rigorous taxation policy ensured that this standard was sustained for the following eleven years. Coinage from this era displays a highly consistent degree of quality including meticulous attention to Domitian's titulature and refined artwork on the reverse portraits. Jones estimates Domitian's annual income at more than 1,200 million sestertii, of which over one-third would presumably have been spent maintaining the Roman army. The other major expense was the extensive reconstruction of Rome. At the time of Domitian's accession the city was still suffering from the damage caused by the Great Fire of 64, the civil war of 69 and the fire in 79. Much more than a renovation project however, Domitian's building program was intended to be the crowning achievement of an Empire-wide cultural renaissance. Around fifty structures were erected, restored or completed, achievements second only to those of Augustus. Among the most important new structures were an odeon, a stadium, and an expansive palace on the Palatine Hill known as the Flavian Palace which was designed by Domitian's master architect Rabirius. The most important building Domitian restored was the Temple of Jupiter on the Capitoline Hill, said to have been covered with a gilded roof. Among those completed were the Temple of Vespasian and Titus, the Arch of Titus, and the Colosseum, to which he added a fourth level and finished the interior seating area.

In order to appease the people of Rome an estimated 135 million sestertii was spent on donatives, or congiaria, throughout Domitian's reign. The Emperor also revived the practice of public banquets, which had been reduced to a simple distribution of food under Nero, while he invested large sums on entertainment and games. In 86 he founded the Capitoline Games, a quadrennial contest comprising athletic displays, chariot racing, and competitions for oratory, music and acting. Domitian himself supported the travel of competitors from all corners of the Empire to Rome and distributed the prizes. Innovations were also introduced into the regular gladiatorial games such as naval contests, nighttime battles, and female and dwarf gladiator fights. Lastly, he added two new factions to the chariot races, Gold and Purple, to race against the existing White, Red, Green and Blue factions.

The military campaigns undertaken during Domitian's reign were generally defensive in nature, as the Emperor rejected the idea of expansionist warfare. His most significant military contribution was the development of the Limes Germanicus, which encompassed a vast network of roads, forts and watchtowers constructed along the Rhine river to defend the Empire. Nevertheless, several important wars were fought in Gaul, against the Chatti, and across the Danube frontier against the Suebi, the Sarmatians, and the Dacians. The conquest of Britain continued under the command of Gnaeus Julius Agricola, who expanded the Roman Empire as far as Caledonia, or modern day Scotland. Domitian also founded a new legion in 82, the Legio I Minervia, to fight against the Chatti. Domitian is also credited on the easternmost Roman evidence known, the rock inscription near Boyukdash mountain, in present day Azerbaijan. As judged by the carved titles of Caesar, Augustus and Germanicus, the related march took place between 84 and 96.

Domitian's administration of the Roman army was characterized by the same fastidious involvement he exhibited in other branches of the government. His competence as a military strategist was criticised by his contemporaries however. Although he claimed several triumphs, these were largely propaganda manoeuvres. Tacitus derided Domitian's victory against the Chatti as a "mock triumph", and criticised his decision to retreat from Britain following the conquests of Agricola. Nevertheless, Domitian appears to have been very popular amongst the soldiers, spending an estimated three years of his reign among the army on campaigns — more than any emperor since Augustus — and raising their pay by one-third. While the army command may have disapproved of his tactical and strategic decisions, the loyalty of the common soldier was unquestioned.

Once Emperor, Domitian immediately sought to attain his long delayed military glory. As early as 82, or possibly 83, he went to Gaul, ostensibly to conduct a census, and suddenly ordered an attack on the Chatti. For this purpose, a new legion was founded, Legio I Minervia, which constructed some 75 kilometres (46 mi) of roads through Chattan territory to uncover the enemy's hiding places. Although little information survives of the battles fought, enough early victories were apparently achieved for Domitian to be back in Rome by the end of 83, where he celebrated an elaborate triumph and conferred upon himself the title of Germanicus. Domitian's supposed victory was much scorned by ancient authors, who described the campaign as "uncalled for", and a "mock triumph". The evidence lends some credence to these claims, as the Chatti would later play a significant role during the revolt of Saturninus in 89.

One of the most detailed reports of military activity under the Flavian dynasty was written by Tacitus, whose biography of his father-in-law Gnaeus Julius Agricola largely concerns the conquest of Britain between 77 and 84. Agricola arrived c. 77 as governor of Roman Britain, immediately launching campaigns into Caledonia: modern day Scotland. In 82 Agricola crossed an unidentified body of water and defeated peoples unknown to the Romans until then. He fortified the coast facing Ireland, and Tacitus recalls that his father-in-law often claimed the island could be conquered with a single legion and a few auxiliaries. He had given refuge to an exiled Irish king whom he hoped he might use as the excuse for conquest. This conquest never happened, but some historians believe that the crossing referred to was in fact a small-scale exploratory or punitive expedition to Ireland. Turning his attention from Ireland, the following year Agricola raised a fleet and pushed beyond the Forth into Caledonia. To aid the advance, a large legionary fortress was constructed at Inchtuthil. In the summer of 84, Agricola faced the armies of the Caledonians, led by Calgacus, at the Battle of Mons Graupius. Although the Romans inflicted heavy losses on the enemy, two-thirds of the Caledonian army escaped and hid in the Scottish marshes and Highlands, ultimately preventing Agricola from bringing the entire British island under his control.

In 85, Agricola was recalled to Rome by Domitian, having served for more than six years as governor, longer than normal for consular legates during the Flavian era. Tacitus claims that Domitian ordered his recall because Agricola's successes outshone the Emperor's own modest victories in Germania. The relationship between Agricola and the Emperor is unclear: on the one hand, Agricola was awarded triumphal decorations and a statue, on the other, Agricola never again held a civil or military post in spite of his experience and renown. He was offered the governorship of the province of Africa, but declined it, either due to ill health or, as Tacitus claims, the machinations of Domitian. Not long after Agricola's recall from Britain, the Roman Empire entered into war with the Kingdom of Dacia in the East. Reinforcements were needed, and in 87 or 88, Domitian ordered a large-scale strategic withdrawal of troops in the British province. The fortress at Inchtuthil was dismantled and the Caledonian forts and watchtowers abandoned, moving the Roman frontier some 120 kilometres (75 mi) further south. The army command may have resented Domitian's decision to retreat, but to him the Caledonian territories never represented anything more than a loss to the Roman treasury.

The most significant threat the Roman Empire faced during the reign of Domitian arose from the northern provinces of Illyricum, where the Suebi, the Sarmatians and the Dacians continuously harassed Roman settlements along the Danube river. Of these, the Sarmatians and the Dacians were the most formidable. In approximately 84 or 85 the Dacians, led by King Decebalus, crossed the Danube into the province of Moesia, wreaking havoc and killing the Moesian governor Oppius Sabinus. Domitian immediately launched a counteroffensive, personally travelling to the region accompanied by a large force commanded by his praetorian prefect Cornelius Fuscus. Fuscus successfully drove the Dacians back across the border in mid 85, prompting Domitian to return to Rome and celebrate his second triumph. The victory proved to be short lived however, as early in 86, Fuscus embarked on an ill-fated expedition into Dacia, which resulted in the complete destruction of the fifth legion, Legio V Alaudae, in the First Battle of Tapae. Fuscus was killed, and the battle standard of the Praetorian Guard was lost. The loss of the battle standard, or aquila, was indicative of a crushing defeat and a serious affront to Roman national pride.

Domitian returned to Moesia in August of 86. He divided the province into Lower Moesia and Upper Moesia, and transferred three additional legions to the Danube. In 87, the Romans invaded Dacia once more, this time under the command of Tettius Julianus, and finally defeated Decebalus in late 88 at the same site where Fuscus had previously perished. An attack on the Dacian capital Sarmizegetusa was forestalled however, when new troubles arose on the German frontier in 89. In order to avert having to conduct a war on two fronts, Domitian agreed to terms of peace with Decebalus, negotiating free access of Roman troops through the Dacian region while granting Decebalus an annual subsidy of 8 million sesterces. Contemporary authors severely criticised this treaty, which was considered shameful to the Romans and left the deaths of Sabinus and Fuscus unavenged. For the remainder of Domitian's reign Dacia remained a relatively peaceful client kingdom, but Decebalus used the Roman money to fortify his defences, and continued to defy Rome. It was not until the reign of Trajan that the Romans achieved a decisive victory against Decebalus in 106. Again, the Roman army sustained heavy losses, but Trajan succeeded in capturing Sarmizegetusa and, importantly, annexed the Dacian gold and silver mines.

Domitian firmly believed in the traditional Roman religion, and personally saw to it that ancient customs and morals were observed throughout his reign. In order to justify the divine nature of the Flavian rule, Domitian emphasized connections with the chief deity Jupiter, perhaps most significantly through the impressive restoration of the Temple of Jupiter on the Capitoline Hill. A small chapel dedicated to Jupiter Conservator was also constructed near the house where Domitian had fled to safety on 20 December, 69. Later in his reign, he replaced it with a more expansive building, dedicated to Jupiter Custos. The goddess he worshipped the most zealously however was Minerva. Not only did he keep a personal shrine dedicated to her in his bedroom, she regularly appeared on his coinage — in four different attested reverse types — and he founded a legion, Legio I Minervia, in her name. Domitian also revived the practice of the imperial cult, which had fallen somewhat out of use under Vespasian. Significantly, his first act as an Emperor was the deification of his brother Titus. Upon their deaths, his infant son, and niece, Julia Flavia, were likewise enrolled among the gods. To foster the worship of the imperial family, he erected a dynastic mausoleum on the site of Vespasian's former house on the Quirinal, and completed the Temple of Vespasian and Titus, a shrine dedicated to the worship of his deified father and brother. To memorialize the military triumphs of the Flavian family, he ordered the construction of the Templum Divorum and the Templum Fortuna Redux, and completed the Arch of Titus.

Construction projects such as these constituted only the most visible part of Domitian's religious policy, which also concerned itself with the fulfilment of religious law and public morals. In 85, he nominated himself perpetual censor, the office which held the task of supervising Roman morals and conduct. Once again, Domitian acquitted himself of this task dutifully, and with care. He renewed the Lex Iulia de Adulteriis Coercendis, under which adultery was punishable by exile. From the list of jurors he struck an equestrian who had divorced his wife and taken her back, while an ex-quaestor was expelled from the Senate for acting and dancing. Domitian also heavily prosecuted corruption among public officials, removing jurors if they accepted bribes and rescinding legislation when a conflict of interest was suspected. He ensured that libellous writings, especially those directed against himself, were punishable by exile or death. Actors were likewise regarded with suspicion, as their performances provided an opportunity for satire at the expense of the government. Consequently, he forbade mimes from appearing on stage in public. In 87, Vestal Virgins were found to have broken their sacred vows of lifelong public chastity. As the Vestals were regarded as daughters of the community, this offence essentially constituted incest. Accordingly, those found guilty of any such transgression were condemned to death, either by a manner of their choosing, or according to the ancient fashion, which dictated that Vestals should be buried alive.

Foreign religions were tolerated insofar as they did not interfere with public order, or could be assimilated with the traditional Roman religion. The worship of Egyptian deities in particular flourished under the Flavian dynasty, to an extent not seen again until the reign of Commodus. Veneration of Serapis and Isis, who were identified with Jupiter and Minerva respectively, was especially prominent. A tradition based upon 4th century writings by Eusebius of Caesarea maintains that Jews and Christians were heavily persecuted toward the end of Domitian's reign. The Book of Revelation is thought to have been written during this period. However no convincing evidence exists of any widespread religious oppression under Domitian. Although Jews were heavily taxed, no contemporary authors mention trials or executions based on religious offences other than those within the Roman religion.

On 1 January 89, the governor of Germania Superior, Lucius Antonius Saturninus, and his two legions at Mainz, Legio XIV Gemina and Legio XXI Rapax, revolted against the Roman Empire with the aid of the Chatti. The precise cause for the rebellion is uncertain, although it appears to have been planned well in advance. The Senatorial officers may have disapproved of Domitian's military strategies, such as his decision to fortify the German frontier rather than attack, as well as his recent retreat from Britain, and finally the disgraceful policy of appeasement towards Decebalus. At any rate, the uprising was strictly confined to Saturninus' province, and quickly detected once the rumour spread across the neighbouring provinces. The governor of Germania Inferior, Lappius Maximus, moved to the region at once, assisted by the procurator of Rhaetia, Titus Flavius Norbanus. From Spain, Trajan was summoned, whilst Domitian himself came from Rome with the Praetorian Guard. By a stroke of luck, a thaw prevented the Chatti from crossing the Rhine and coming to Saturninus' aid. Within twenty-four days the rebellion was crushed, and its leaders at Mainz savagely punished. The mutinous legions were sent to the front in Illyricum, while those who had assisted in their defeat were duly rewarded.

Lappius Maximus received the governorship of the province of Syria, a consulship in May of 95, and finally a priesthood which he still held in 102. Titus Flavius Norbanus may have been appointed to the prefecture of Egypt, but almost certainly became prefect of the Praetorian Guard by 94, with Titus Petronius Secundus as his colleague. Domitian opened the year following the revolt by sharing the consulship with Marcus Cocceius Nerva, suggesting the latter had played a part in uncovering the conspiracy, perhaps in a fashion similar to the one he played during the Pisonian conspiracy under Nero. Although little is known about the life and career of Nerva before his accession as Emperor in 96, he appears to have been a highly adaptable diplomat, surviving multiple regime changes and emerging as one of the Flavians' most trusted advisors. His consulship may therefore have been intended to emphasise the stability and status quo of the regime. The revolt had been suppressed and the Empire returned to order.

Since the fall of the Republic, the authority of the Roman Senate had largely eroded under the quasi-monarchical system of government established by Augustus, known as the Principate. The Principate allowed the existence of a de facto dictatorial regime, while maintaining the formal framework of the Roman Republic. Most Emperors upheld the public facade of democracy, and in return the Senate implicitly acknowledged the Emperor's status as a de facto monarch. Some rulers handled this arrangement with less subtlety than others however, among them Domitian. From the outset of his reign, he stressed the reality of his autocracy. He disliked aristocrats and had no fear of showing it, withdrawing every decision making power from the Senate, and instead relying on a small set of friends and equestrians to control the important offices of state. The dislike was mutual. After Domitian's assassination, the senators of Rome rushed to the Senate house, where they immediately passed a motion condemning his memory to oblivion. Under the rulers of the Nervan-Antonian dynasty, senatorial authors published histories which elaborated on the view of Domitian as a tyrant.

Nevertheless, the evidence suggests that Domitian did make concessions toward senatorial opinion. Whereas his father and brother had concentrated consular power largely in the hands of the Flavian family, Domitian admitted a surprisingly large number of provincials and potential opponents to the consulship, allowing them to head the official calendar by opening the year as an ordinary consul. Whether this was a genuine attempt to reconcile with hostile factions in the Senate cannot be ascertained. By offering the consulship to potential opponents, Domitian may have wanted to compromise these senators in the eyes of their supporters. When their conduct proved unsatisfactory, they were almost invariably brought to trial and exiled or executed, and their property was confiscated. Both Tacitus and Suetonius speak of escalating persecutions toward the end of Domitian's reign, identifying a point of sharp increase around 93, or sometime after the failed revolt of Saturninus in 89. At least twenty senatorial opponents were executed, including Domitia Longina's former husband Lucius Aelius Lamia and three of Domitian's own family members, Titus Flavius Sabinus IV, Titus Flavius Clemens and Marcus Arrecinus Clemens. Some of these men were executed as early as 83 or 85 however, lending little credit to Tacitus' notion of a "reign of terror" late in Domitian's reign. According to Suetonius, some were convicted for corruption or treason, others on trivial charges, which Domitian justified through his suspicion:

He used to say that the lot of Emperors was most unfortunate, since when they discovered a conspiracy, no one believed them unless they had been murdered.

Suetonius, De Vita Caesarum, "Life of Domitian"

Jones compares the executions of Domitian to those under Emperor Claudius (41 – 55), noting that Claudius executed around 35 senators and 300 equestrians, and yet was still deified by the Senate and regarded as one of the good Emperors of history. Domitian was apparently unable to gain support among the aristocracy, despite attempts to appease hostile factions with consular appointments. His autocratic style of government accentuated the Senate's loss of power, while his policy of treating patricians and even family members as equals to all Romans earned him their contempt.

Domitian was murdered on 18 September 96, in a palace conspiracy organized by court officials. A highly detailed account of the plot and the assassination is provided by Suetonius, who alleges that Domitian's chamberlain Parthenius was the chief instigator behind the conspiracy, citing the recent execution of Domitian's secretary Epaphroditus as the primary motive. The murder itself was carried out by a freedman of Parthenius named Maximus, and a steward of Domitian's niece Flavia Domitilla, named Stephanus. The precise involvement of the Praetorian Guard is less clear. At the time the Guard was commanded by Titus Flavius Norbanus and Titus Petronius Secundus and the latter was almost certainly aware of the plot. Cassius Dio, writing nearly a hundred years after the assassination, includes Domitia Longina among the conspirators, but in light of her attested devotion to Domitian — even years after her husband had died — her involvement in the plot seems highly unlikely. Dio further suggests that the assassination was improvised, while Suetonius implies a well organised conspiracy. For some days before the attack took place, Stephanus feigned an injury so as to be able to conceal a dagger beneath his bandages. On the day of the assassination the doors to the servants' quarters were locked while Domitian's personal weapon of last resort, a sword he concealed beneath his pillow, had been removed in advance. In accordance with an astrological prediction the emperor believed that he would die around noon, and was therefore restless during this time of the day. On his last day, Domitian was feeling disturbed and asked a servant several times what time it was. The boy, included in the plot, lied, saying that it was much later than noon. More at ease, the emperor went to his desk to sign some decrees, where he was suddenly approached by Stephanus:

Then pretending to betray a conspiracy and for that reason being given an audience, [Stephanus] stabbed the emperor in the groin as he was reading a paper which the assassin handed him, and stood in a state of amazement. As the wounded prince attempted to resist, he was slain with seven wounds by Clodianus, a subaltern, Maximus, a freedman of Parthenius, Satur, decurion of the chamberlains, and a gladiator from the imperial school.

Suetonius, De Vita Caesarum, "Life of Domitian"

Domitian and Stephanus wrestled on the ground for some time, until the emperor was finally overpowered and fatally stabbed by the conspirators. Around noon Domitian, just one month short of his 45th birthday, was dead. His body was carried away on a common bier, and unceremoniously cremated by his nurse Phyllis, who later mingled the ashes with those of his niece Julia, at the Flavian temple. According to Suetonius, a number of omens had foretold Domitian's death. Several days prior to the assassination, Minerva had appeared to him in a dream, announcing she had been disarmed by Jupiter, and would no longer be able to protect him.

The Fasti Ostienses, the Ostian Calendar, records that the same day the Senate proclaimed Marcus Cocceius Nerva emperor. Despite his political experience, this was a remarkable choice. Nerva was old and childless, and had spent much of his career out of the public light, prompting both ancient and modern authors to speculate on his involvement in Domitian's assassination. According to Cassius Dio, the conspirators approached Nerva as a potential successor prior to the assassination, suggesting that he was at least aware of the plot. He does not appear in Suetonius' version of the events, but this may be understandable, since his works were published under Nerva's direct descendants Trajan and Hadrian. To suggest the dynasty owed its accession to murder would have been less than sensitive. On the other hand, Nerva lacked widespread support in the Empire, and as a known Flavian loyalist, his track record would not have recommended him to the conspirators. The precise facts have been obscured by history, but modern historians believe Nerva was proclaimed Emperor solely on the initiative of the Senate, within hours after the news of the assassination broke. The decision may have been hasty so as to avoid civil war, but neither appears to have been involved in the conspiracy.

The Senate nonetheless rejoiced at the death of Domitian, and immediately following Nerva's accession as Emperor, passed damnatio memoriae on his memory: his coins and statues were melted, his arches were torn down and his name was erased from all public records. Domitian and, over a century later Publius Septimius Geta, were the only emperors known to have officially received a damnatio memoriae, though others may have received de facto ones. In many instances, existing portraits of Domitian, such as those found on the Cancelleria Reliefs, were simply recarved to fit the likeness of Nerva, which allowed quick production of new images and recycling of previous material. Yet the order of the Senate was only partially executed in Rome, and wholly disregarded in most of the provinces outside Italy.

According to Suetonius, the people of Rome met the news of Domitian's death with indifference, but the army was much grieved, calling for his deification immediately after the assassination, and in several provinces rioting. As a compensation measure, the Praetorian guard demanded the execution of Domitian's assassins, which Nerva refused. Instead he merely dismissed Titus Petronius Secundus, and replaced him with a former commander, Casperius Aelianus. Dissatisfaction with this state of affairs continued to loom over Nerva's reign, and ultimately erupted into a crisis in October of 97, when members of the Praetorian guard, led by Casperius Aelianus, laid siege to the Imperial Palace and took Nerva hostage. He was forced to submit to their demands, agreeing to hand over those responsible for Domitian's death and even giving a speech thanking the rebellious Praetorians. Titus Petronius Secundus and Parthenius were sought out and killed. Nerva was unharmed in this assault, but his authority was damaged beyond repair. Shortly thereafter he announced the adoption of Trajan as his successor, and with this decision all but abdicated.

The classic view of Domitian is usually negative, since most of the antique sources were related to the Senatorial or aristocratic class, with which Domitian had a notoriously difficult relation. Furthermore, contemporary historians such as Pliny the Younger, Tacitus and Suetonius all authored the information on his reign after it had ended, and his memory had been condemned to oblivion. The work of Domitian's court poets Martial and Statius constitutes virtually the only literary evidence concurrent with his reign. Perhaps equally unsurprising as the attitude of post-Domitianic historians, the poems of Martial and Statius are highly adulatory, praising Domitian's achievements as equalling those of the gods. The most extensive account of the life of Domitian to survive was written by the historian Suetonius, who was born during the reign of Vespasian, and published his works under Emperor Hadrian (117 – 138). His De Vita Caesarum is the source of much of what is known of Domitian. Although his text is predominantly negative, it neither exclusively condemns nor praises Domitian, and asserts that his rule started well, but gradually declined into terror. The biography is problematic however, in that it appears to contradict itself with regards to Domitian's rule and personality, at the same time presenting him as a conscientious, moderate man, and as a decadent libertine. According to Suetonius, Domitian wholly feigned his interest in arts and literature, and never bothered to acquaint himself with classic authors. Other passages, alluding to Domitian's love of epigrammatic expression, suggest that he was in fact familiar with classic writers, while he also patronized poets and architects, founded artistic olympics, and personally restored the library of Rome at great expense after it had burned down.

De Vita Caesarum is also the source of several outrageous stories regarding Domitian's marriage life. According to Suetonius, Domitia Longina was exiled in 83 because of an affair with a famous actor named Paris. When Domitian found out, he allegedly murdered Paris in the street and promptly divorced his wife, with Suetonius further adding that once Domitia was exiled, Domitian took Julia as his mistress, who later died during a failed abortion. Modern historians consider this highly implausible however, noting that malicious rumours such as those concerning Domitia's alleged infidelity were eagerly repeated by post-Domitianic authors, and used to highlight the hypocrisy of a ruler publicly preaching a return to Augustan morals, while privately indulging in excesses and presiding over a corrupt court.Nevertheless, the account of Suetonius has dominated imperial historiography for centuries.

Although Tacitus is usually considered to be the most reliable author of this era, his views on Domitian are complicated by the fact that his father-in-law, Gnaeus Julius Agricola, may have been a personal enemy of the Emperor. In his biographical work Agricola, Tacitus maintains that Agricola was forced into retirement because his triumph over the Caledonians highlighted Domitian's own inadequacy as a military commander. Several modern authors such as Dorey have argued the opposite: that Agricola was in fact a close friend of Domitian, and that Tacitus merely sought to distance his family from the fallen dynasty once Nerva was in power. Tacitus' major historical works, including The Histories and Agricola's biography, were all written and published under Domitian's successors Nerva (96 – 98) and Trajan (98 – 117). Unfortunately, the part of Tacitus' Histories dealing with the reign of the Flavian dynasty is almost entirely lost. His views on Domitian survive through brief comments in its first five books, and the short but highly negative characterisation in Agricola in which he severely criticises Domitian's military endeavours. Nevertheless, Tacitus admits his debt to the Flavians with regard to his own public career.

Other influential 2nd century authors include Juvenal and Pliny the Younger, the latter whom was a friend of Tacitus and in 100 delivered his famous Panygericus Traiani before Trajan and the Roman Senate, exalting the new era of restored freedom while condemning Domitian as a tyrant. Juvenal savagely satirized the Domitianic court in his Satires, depicting the Emperor and his entourage as corrupt, violent and unjust. As a consequence, the anti-Domitianic tradition was already well established by the end of the 2nd century, and by the 3rd century, even expanded upon by early Church historians, who identified Domitian as an early persecutor of Christians.

Hostile views of Domitian were propagated until well into the early 20th century, before archeological and numismatic advances brought renewed attention to his reign, and necessitated a revision of the literary tradition established by Tacitus and Pliny. In 1930, Ronald Syme argued a complete reassessment of Domitian's financial policy, which had until then been largely viewed as a disaster, opening his paper with the following introduction:

The work of the spade and the use of common sense have done much to mitigate the influence of Tacitus and Pliny and redeem the memory of Domitian from infamy or oblivion. But much remains to be done.

Ronald Syme, Imperial finances under Domitian, Nerva and Trajan

Over the course of the 20th century, Domitian's military, administrative and economic policies were re-evaluated. New book length studies were not published until the 1990s however, nearly a hundred years after Stéphane Gsell's Essai sur le règne de l'empereur Domitien (1894). The most important of these was The Emperor Domitian, by Brian W. Jones. In his monograph, Jones concludes that Domitian was a ruthless, but efficient autocrat. For the majority of his reign, there was no widespread dissatisfaction with the emperor or his rule. His harshness was felt by only a small, but highly vocal minority, who later exaggerated his despotism in favour of the well regarded Nervan - Antonian dynasty which followed.