Gnaeus Pompeius Magnus, also known as Pompey or Pompey the Great (September 29, 106 BC – September 29, 48 BC), was a military and political leader of the late Roman Republic. He came from a wealthy Italian provincial background, and established himself in the ranks of Roman nobility by successful leadership in several campaigns. Sulla addressed him by the cognomen Magnus (the Great) and he was awarded three triumphs.

Pompey joined his rival Marcus Licinius Crassus and his ally and father-in-law Julius Caesar in the military-political alliance known as the First Triumvirate. After the deaths of Crassus and Julia, Pompey's wife and Caesar's daughter, Pompey and Caesar contended the leadership of the Roman state in a civil war. Pompey sided with the optimates, the conservative and aristocratic majority of the Roman Senate. When Caesar defeated him at the battle of Pharsalus he sought refuge in Egypt, where he was assassinated. His career and defeat are significant in Rome's subsequent transformation from Republic to Principate and Empire.

Pompey's father, Gnaeus Pompeius Strabo, was a wealthy landed Italian provincial from Picenum, one of the "new men" whose influence would increasingly dominate Roman politics in the Late Republic. Pompeius Strabo ascended the traditional cursus honorum, becoming quaestor in 104 BC, praetor in 92 BC and consul in 89 BC, and acquired a reputation for greed, political double-dealing and military ruthlessness. He supported Sulla's traditionalist optimates against the popularist general Marius in the first Marian-Sullan war. He died during the Sullan campaign against the Italians in 87 BC, either as a casualty of pandemic plague, or struck by lightning, or possibly both. In Plutarch's account, his body was dragged from its bier by the mob. His nineteen-year-old son Pompey inherited his estates, his political leanings and the loyalty of his legions.

Pompey had served two years under his father's command, and was involved in the final acts of the Marsic Social War against the Italians. He returned to Rome and was prosecuted for misappropriation of plunder: his betrothal to the judge's daughter Antistia secured a rapid acquittal.

For the next few years, the Marians had possession of Italy. When Sulla returned from campaign against Mithridates in 83 BC, Pompey raised three Picenean legions to support him against the Marian regime of Gnaeus Papirius Carbo. Sulla and his allies displaced the Marians in Italy and Rome: Sulla, now Dictator of Rome, was impressed by the young Pompey's self-confident performance. He addressed him as imperator and offered his stepdaughter Aemilia Scaura in marriage. Aemilia – already married and pregnant – divorced her husband and Pompey divorced Antistia. Though Aemilia died in childbirth soon after, the marriage confirmed Pompey's loyalty and greatly boosted his career. With the war in Italy over, Sulla sent Pompey against the Marians in Sicily and Africa. In 82 BC, Pompey secured Sicily, guaranteeing Rome's grain supply. He executed Gnaeus Papirius Carbo and his supporters out of hand, which may have led to his dubbing as the adulescens carnifex meaning "adolescent butcher". In 81 BC he moved on to the Roman province of Africa, where he defeated Gnaeus Domitius Ahenobarbus and the Numidian king Hiarbas, after a hard-fought battle. After this string of victories, Pompey was proclaimed Imperator by his troops on the field in Africa; once back in Rome, he was given an enthusiastic popular reception and hailed by Sulla as Magnus ("the Great") – probably in recognition of Pompey's undoubted victories and popularity but also with some degree of sarcasm. The young general was still officially a mere privatus (private citizen) who had held no offices in the cursus honorum. The title may have been meant to cut Pompey down to size; he himself used it only later in his career.

When Pompey demanded a triumph for his African victories, Sulla refused: it would be an unprecedented, even illegal honour for a young privatus – he must disband his legions. Pompey refused, and presented himself expectantly at the gates of Rome: Sulla gave in. However, Sulla had his own triumph first, then allowed Metellus Pius his triumph, relegating Pompey to an extra-legal third place in a quick succession of triumphs. On the day, Pompey attempted to upstage both his seniors in a triumphal chariot towed by an elephant, representing his exotic African conquests. The elephant would not fit through the city gate. Some hasty re-planning was needed, much to the embarrassment of Pompey and amusement of those present. His refusal to give in to his troops' near-mutinous demands for cash probably impressed his mentor and Rome's conservatives.

Pompey's career seems to have been driven by desire for military glory and disregard for traditional political constraints. In the consular elections of 78 BC, he supported Lepidus against Sulla's wishes. In 78, Sulla died; when Lepidus revolted, Pompey suppressed him on behalf of the senate. Then he asked for proconsular imperium in Hispania to deal with the Marian general Quintus Sertorius, who had held out for the past three years against Quintus Caecilius Metellus Pius, one of Sulla's most able generals. The Roman aristocracy turned him down – they were beginning to fear the young, popular and successful general. Pompey resorted to his tried and tested persuasion; he refused to disband his legions until his request was granted. The senate acceded, reluctantly granted him the title of proconsul and powers equal to those of Metellus, and sent him to Hispania.

Pompey remained there from 76 – 71 BC. Sertorius was murdered by his own officer Marcus Perperna Vento, who was defeated in 72 by Pompey, at their first battle. By early 71 the whole of Hispania was subdued. Pompey showed a talent for efficient organisation and fair administration in the conquered province; this extended his patronage throughout Hispania and into southern Gaul. Some time in 71 BC, he set off for Italy, along with his army.

Meanwhile, Crassus was facing Spartacus to end Rome's Third Servile War. Crassus defeated Spartacus; but in his march towards Rome, Pompey encountered the remnants of Spartacus' army, captured five thousand of them and claimed the credit for finishing the revolt; this infuriated Crassus.

Back in Rome, Pompey was wildly popular. On December 31, 71 BC, he was given a triumph for his victories in Hispania – like his first, it was granted extralegally. To his admirers he was the most brilliant general of the age, evidently favoured by the gods and a possible champion of the people's rights. He had successfully faced down Sulla and his senate; he or his influence might restore the traditional plebian rights and privileges lost under Sulla's dictatorship. So Pompey was allowed to bypass another ancient Roman tradition; at only 35 years of age and while not even a senator, he was elected Consul by an overwhelming majority vote, and served in 70 BC with Crassus as partner. Pompey's leap from mere eques to Consul was not simply unprecedented; his tactics offended the traditionalist nobility whose values he claimed to share and defend. He had left them no option but to allow his consulship and they probably never forgave him.

Two years after his consulship, Pompey was offered command of a naval task force to deal with piracy in the Mediterranean Sea. The conservative faction of the Senate remained suspicious and wary of him; this seemed yet another illegal or at least extraordinary appointment. Pompey's supporters for this command – including Caesar – were in the minority, but support was whipped up through his nomination by the Tribune of the Plebs Aulus Gabinius who proposed a Lex Gabinia; Pompey should have control over the sea and the coasts for 50 miles inland. This would set him above every military leader in the East – it was passed despite vehement opposition. According to Rome's historians, pirates had freely plundered the coastal cities of Greece, Asia and Italy itself. The extent and nature of their threat is questionable: anything that threatened Rome's grain supply was cause for panic. Roman public opinion and Pompey's supporters may have exaggerated the problem. Various settlements, peoples and city-states around the Mediterranean had co-existed several centuries and most had operated small fleets for war, or trade in commodities, including slaves. Their alliances might be loose and temporary or more-or-less permanent; some regarded themselves as nations. With Rome's increasing hegemony, the independent maritime economies of the Mediterranean would have been further marginalised; an increasing number would have resorted to piracy. As long as they met Rome's increasing requirement for slaves, left her allies and territories untouched and offered her enemies no support, they were tolerated. Some were subsidised. But fear of piracy was potent – and these same pirates, it was later alleged, had assisted Sertorius.

By the end of that winter, the preparations were complete. Pompey allocated one of thirteen areas to each of his legates, and sent out their fleets. In forty days the Western Mediterranean was cleared. Dio reports that communication was restored between Hispania, Africa, and Italy; and that Pompey then attended to the largest of these alliances, centered on the coast of "Rough Cilicia". After "defeating" its fleet, he induced its surrender with promises of pardon, and settled many of its people at Soli, which was henceforward called Pompeiopolis. De Souza (2002) finds that Pompey had officially returned the Cilicians to their own cities, which were ideal bases for piracy and not – as Dio would have it – for the dignified reformation of pirates as farmers. Pompey's entire campaign is therefore in question; its description as "war" is hyperbole – some form of treaty or pay-off is likely, with Pompey as chief negotiator. This was standard practice but undignified and seldom acknowledged; Rome's generals were supposed to wage and win wars. A decade on, in the 50's BC, the Cilicians and pirates in general remained a nuisance to Rome's sea-trade.

In Rome, however, Pompey was hero; once again, he had guaranteed the grain supply. According to Plutarch, by the end of the summer of 66 BC his forces had swept the Mediterranean clear of opposition. Pompey was hailed as the first man in Rome, "Primus inter pares" the first among equals. Cicero could not resist a panegyric:

"Pompey made his preparations for the war at the end of the winter, entered upon it at the commencement of spring, and finished it in the middle of the summer."

The expedience of his campaign probably guaranteed Pompey his next and even more impressive command, this time in Rome's long-running war against Mithridates. By the 40's BC Cicero could comment less favourably on the pirate campaign, and especially the funded "resettlement" at Soli/Pompeiopolis; "we give immunity to pirates and make our allies pay tribute." Pompey spent the rest of that year and the beginning of the next visiting the cities of Cilicia and Pamphylia, and providing for the government of newly conquered territories. In his absence from Rome (66 BC) he was nominated to succeed Lucius Licinius Lucullus as commander in the Third Mithridatic War against Mithridates VI of Pontus in the East. Lucullus, a plebeian noble, was incensed at the prospect of his replacement by a "new man" such as Pompey. The outgoing commander and his replacements traded insults. Lucullus called Pompey a "vulture" who fed from the work of others. Pompey's command was proposed by the tribune Gaius Manilius, supported by Caesar and justified by Cicero in pro Lege Manilia. Like the Gabinian law, it was opposed by the aristocracy, but was carried nonetheless. The power of Mithridates had been worn down by previous victories of Lucullus; Pompey had only to conclude the war and reorganise the Eastern Mediterranean. At Pompey's approach, Mithridates strategically withdrew his forces. Tigranes the Great refused him refuge so he made his way to his own dominions in the Cimmerian Bosporus. Pompey secured a treaty with Tigranes and in 65 BC set out in pursuit of Mithridates but met resistance from the Caucasian Iberians and Albanians. He advanced to Phasis in Colchis and liaised with his legate Servilius, admiral of his Euxine fleet. Pompey then retraced his steps, wintered at Pontus and made it into a Roman province. In 64 BC he marched into Syria, deposed its king, Antiochus XIII Asiaticus and reconstituted this too as a Roman province. In 63 BC, he moved south, and established Roman supremacy in Phoenicia and Coele-Syria.

In Judea, Pompey intervened in civil war between Hyrcanus II, who supported the Pharisee faction against Aristobulus II and the Sadducees in Judaea's civil war. The armies of Pompey and Hyrcanus II laid siege to Jerusalem. After three months, the city fell.

"Of the Jews there fell twelve thousand, but of the Romans very few.... and no small enormities were committed about the temple itself, which, in former ages, had been inaccessible, and seen by none; for Pompey went into it, and not a few of those that were with him also, and saw all that which it was unlawful for any other men to see but only for the high priests. There were in that temple the golden table, the holy candlestick, and the pouring vessels, and a great quantity of spices; and besides these there were among the treasures two thousand talents of sacred money: yet did Pompey touch nothing of all this, on account of his regard to religion; and in this point also he acted in a manner that was worthy of his virtue. The next day he gave order to those that had the charge of the temple to cleanse it, and to bring what offerings the law required to God; and restored the high priesthood to Hyrcanus, both because he had been useful to him in other respects, and because he hindered the Jews in the country from giving Aristobulus any assistance in his war against him." Josephus, Antiquitates Judaicae, book 14, chapter 4; tr. by William Whiston, available at Project Gutenberg

During the war in Judea, Pompey heard of Mithridates' suicide; his army had deserted him for his son Pharnaces. Rome's Asian protectorates now extended as far east as the Black Sea and the Caucasus. Pompey's political settlements and annexations in Asia created Rome's new frontier on the East.

News of Pompey victories in the East – and probably of his divine honours there – reached Rome before he did. He had cult at Delos and was "saviour" in Samos and Mytelene. Plutarch quotes a wall-graffito in Athens, referring it to Pompey: "The more you know you're a man, the more you become a god". In Greece, these honours were standard fare for benefactors. In Rome, they would have seemed dangerously monarchic. In Pompey's absence, his old supporter Cicero had risen to the consulship, then been forced into exile by his popularist opponents. His old enemy and colleague Crassus supported Caesar. In the Senate and behind its scenes, Pompey was probably equally admired, feared and excluded; on the streets he was as popular as ever. His Eastern victories earned him his third triumph. On his 45th birthday, in 61 BC, he rode the triumphal chariot, a magnificent god-king but one of Republican form, ritualistically reminded of his impermanence and mortality. Even so, he was accompanied by a gigantic portrait head of himself, studded with pearls. His third triumph exceeded all others; an unprecedented two days were scheduled for its procession and games (ludi). Spoils, prisoners, army and banners depicting battle scenes wended the triumphal route between the Campus Martius and the Capitoline temple of Jupiter. To conclude, he gave an immense triumphal banquet and money to the people of Rome, and promised them a new theatre. Plutarch claimed that this triumph represented Pompey's - and therefore Rome's - domination over the entire world, an achievement to outshine even Alexander's. In the meantime, Pompey promised his retiring veterans public lands to farm, then dismissed his armies. It was a reassuringly traditional gesture but the senate remained suspicious. They debated and delayed his Eastern political settlements and the promised gifts of public land. From now on, Pompey seems to have toed a cautious line between his enthusiastic popular supporters and the conservatives who seemed so reluctant to acknowledge his solid achievements. It would lead him into unexpected political alliances.

Although Pompey and Crassus distrusted each other, Crassus' tax farming clients were being rebuffed at the same time that Pompey's veterans were being ignored, and by 61 BC their grievances had pushed them both into an alliance with Caesar, 6 years younger than Pompey, returning from service in Hispania, and ready to seek the consulship for 59 BC. Their political alliance, known as the First Triumvirate operated to the benefit of each. Pompey and Crassus would make Caesar Consul, and Caesar would use his consular power to promote their claims. Caesar's consulship of 59 BC brought Pompey land for his veterans, confirmation of his Asian political settlements and a new wife. She was Caesar's daughter, Julia; Pompey was said to be besotted by her. In the same year, Clodius renounced his patrician status, was adopted into a plebian gens and was elected a Tribune of the plebs. At the end of his consulship, Caesar secured proconsular command in Gaul. Pompey was given the governorship of Hispania Ulterior but remained in Rome to oversee Rome's critical Roman grain supply as curator annonae.

Despite his preoccupation with his new wife, Pompey handled the grain issue well. His political acumen was less sure. When Clodius turned on him in turn, Pompey defended himself by supporting Cicero's recall from exile (57 BC). Once back in Rome, Cicero stepped back into his role as Pompey's defender and Clodius' antagonist but Pompey himself retreated to his lovely young wife and his theatre plans: such behaviour was not expected of the once dazzling young general. Pompey might equally have been obsessed, exhausted and frustrated. His own party had not forgiven him for allowing Cicero's expulsion. Some tried to persuade him that Crassus was plotting his assassination. Meanwhile, Caesar seemed set on outstripping both his colleagues in generalship and popularity. By 56 BC, the bonds between the three men were fraying. Caesar was no longer the amenable silent partner of the trio. He called first Crassus, then Pompey, to a secret meeting in the northern Italian town of Lucca to rethink their joint strategy. They agreed that Pompey and Crassus would again stand for the consulship in 55 BC. Once elected, they would extend Caesar's command in Gaul by five years. At the end of their joint consular year, Crassus would have the influential and lucrative governorship of Syria, and use this as a base to conquer Parthia. Pompey would keep Hispania in absentia.

In 55 BC Pompey and Crassus were elected as consuls, against a background of bribery, civil unrest and electioneering violence. Pompey's new theatre was inaugurated in the same year. It was Rome's first permanent theatre, a gigantic, architecturally daring, self-contained complex on the Campus Martius, complete with shops, multi-service buildings, gardens and a temple to Venus Victrix. The latter connected its donor to Aeneas, a son of Venus and ancestor of Rome itself. In its portico, the statuary, paintings and personal wealth of foreign kings could be admired at leisure; Pompey's triumph lived on. His theatre made an ideal meeting-place for his supporters. In 54 BC, Julia, Caesar's only child and Pompey's wife, died in childbirth along with her baby. Pompey and Caesar shared their grief and condolences, but Julia's death broke their family bonds. The following year, Crassus, his son Publius and most of his army were annihilated by the Parthians at Carrhae. Caesar, not Pompey, was now Rome's great new general and the fragile balance of power between them was under threat. Public anxiety spilled over: rumours circulated that Pompey would be offered dictatorship for the sake of law and order. Caesar sought a second matrimonial alliance with Pompey, offering his grandniece Octavia (the sister of the future emperor Augustus). This time, Pompey refused. In 52 BC, he married Cornelia Metella, the very young widow of Crassus's son Publius, and the daughter of Caecilius Metellus Scipio, one of Caesar’s greatest enemies. Pompey was drifting back toward the Optimates. It can be presumed that they thought him the lesser of two evils.

In the same year, Publius Clodius was murdered. When his supporters burned down the Senate House in retaliation, the Senate appealed to Pompey. He reacted with ruthless efficiency. Cicero, defending the accused murderer Titus Annius Milo, was so shaken by a Forum seething with armed soldiers that he was unable to complete his defense. Once order was restored the Senate and Cato avoided granting Pompey dictatorship – it recalled Sulla and his bloody proscriptions. Instead they made him sole Consul; this gave him sweeping but limited powers. A Dictator could not be lawfully punished for measures taken during his office. As sole Consul, Pompey would be answerable for his actions once out of office.

While Caesar was fighting against Vercingetorix in Gaul, Pompey proceeded with a legislative agenda for Rome. Its details suggested covert alliance with Caesar's enemies: among his various legal and military reforms was a law allowing retrospective prosecution for electoral bribery. Caesar's allies correctly interpreted this as a threat to Caesar once his imperium ended. Pompey also prohibited Caesar from standing for the consulship in absentia, though this had been permitted under past laws. This seemed to put paid to Caesar's plans after his term in Gaul expired. Finally, in 51 BC, Pompey was more forthright: Caesar would not be permitted to stand for Consul unless he relinquished his armies. This would, of course, leave Caesar defenseless before his enemies. As Cicero sadly noted, Pompey had been diminished by age, uncertainty, his fear of Caesar and the strain of being the chosen tool of a quarreling oligarchy of Optimates. The coming conflict seemed inevitable.

In the beginning, Pompey claimed he could defeat Caesar and raise armies merely by stamping his foot on the soil of Italy, but by the spring of 49 BC, with Caesar crossing the Rubicon and his invading legions sweeping down the peninsula, Pompey ordered the abandonment of Rome. His legions retreated south towards Brundisium, where Pompey intended to find renewed strength by waging war against Caesar in the East. In the process, neither Pompey nor the Senate thought of taking the vast treasury with them, probably thinking that Caesar would not dare take it for himself. It was left conveniently in the Temple of Saturn when Caesar and his forces entered Rome. Barely eluding Caesar in Brundisium, Pompey crossed over into Epirus where during Caesar's Spanish campaign, Pompey had gathered a large force in Macedonia, comprising nine legions reinforced by contingents from the Roman allies in the east. His fleet, recruited from the maritime cities in the east, controlled the Adriatic. Nevertheless, Caesar managed to cross over into Epirus in November 49 BC and proceeded to capture Apollonia. Pompey managed to arrive in time to save Dyrrhachium, and he then attempted to wait Caesar out during the siege of Dyrrhachium, in which Caesar lost 1000 men. Yet, by failing to pursue at the critical moment of Caesar's defeat, Pompey threw away the chance to destroy Caesar's much smaller army. As Caesar himself said, "Today the enemy would have won, if they had had a commander who was a winner" (Plutarch, 65). According to Suetonius, it was at this point that Caesar said that "that man (Pompey) does not know how to win a war." With Caesar on their backs, the conservatives led by Pompey fled to Greece. Caesar and Pompey had their final showdown at the Battle of Pharsalus in 48 BC. The fighting was bitter for both sides and although Pompey was expected to win due to advantage in numbers, mistakes made by Pompey's front cavalry horsemen led to a victory for Caesar. Like all the other conservatives, Pompey had to run for his life. He met his wife Cornelia and his son Sextus Pompeius on the island of Mytilene. He then wondered where to go next. The decision of running to one of the eastern kingdoms was overruled in favor of Egypt.

After his arrival in Egypt, Pompey's fate was decided by the counselors of the young king Ptolemy XIII. While Pompey waited offshore, they argued the cost of offering him refuge with Caesar already en route to Egypt: the king's eunuch Pothinus won out. In the final dramatic passages of his biography, Plutarch had Cornelia watch anxiously from the trireme as Pompey left in a small boat with a few sullen, silent comrades and headed for what appeared to be a welcoming party on the Egyptian shore. As Pompey rose to disembark, he was stabbed to death by his betrayers Achillas, Septimius and Salvius. Plutarch has him meet his fate with great dignity, one day after his 59th birthday. His body remained on the shoreline, to be cremated by his loyal freeman Philip on the rotten planks of a fishing-boat. His head and seal were later presented to Caesar, who not only mourned this insult to the greatness of his former ally and son-in-law (he wept when he received Pompey's seal, on which there was an engraving of a lion holding a sword in his paw), and punished his assassins and their Egyptian co-conspirators, putting both Achillas and Pothinus to death. Pompey's ashes were eventually returned to Cornelia, who carried them to his country house near Alba. Cassius Dio describes Caesar's reactions with skepticism, and considers Pompey's own political misjudgements, rather than treachery, as instrumental in his downfall. For Pliny, the humiliation of his end is anticipated by the vaunting pride of Pompey's oversized portrait-head, studded entirely with pearls, carried in procession during his greatest Triumph.

To the historians of his own and later Roman periods, Pompey fulfilled the trope of the great man who achieved extraordinary triumphs through his own efforts, yet fell from power and was, in the end, murdered through treachery. He was a hero of the Republic, who seemed once to hold the Roman world in his palm only to be brought low by his own poor judgment and Caesar. Pompey was idealized as a tragic hero almost immediately after Pharsalus and his murder: Plutarch portrayed him as a Roman Alexander the Great, pure of heart and mind, destroyed by the cynical ambitions of those around him. This portrayal of him survived into the Renaissance and Baroque periods, for example in Corneille's play The Death of Pompey (1642).