Shāh ‘Abbās the Great or Shāh ‘Abbās I (Persian: شاه عباس بزرگ) (born January 27, 1571; died January 19, 1629) was Shah (king) of Iran, and the greatest ruler of the Safavid dynasty. He was the third son of Shah Mohammad.

Abbas came to the throne during a troubled time for Iran. Under his weak-willed father, the country was riven with discord between the different factions of the Qizilbash army, who killed Abbas' mother and elder brother. Meanwhile, Iran's enemies, the Ottoman Empire and the Uzbeks, exploited this political chaos to seize territory for themselves. In 1587, one of the Qizilbash leaders, Murshid Qoli Khan, overthrew Shah Mohammed in a coup and placed the 16-year-old Abbas on the throne. But Abbas was no puppet and soon seized power for himself. He reduced the influence of the Qizilbash in the government and the military and reformed the army, enabling him to fight the Ottomans and Uzbeks and reconquer Iran's lost provinces. He also took back land from the Portuguese and the Mughals. Abbas was a great builder and moved his kingdom's capital from Qazvin to Isfahan. In his later years, the shah became suspicious of his own sons and had them killed or blinded.

Abbas was born in Herat (now in Afghanistan, then one of the two chief cities of Khorasan) to the royal prince Mohammed Khodabanda and his wife Khayr al-Nisa Begum (known as "Mahd-i Ulya"), the daughter of the governor of Mazandaran province, who claimed descent from the fourth Shi'a Imam Zayn al-Abidin. At the time of his birth, Abbas' grandfather Shah Tahmasp I was ruler of Iran. 

In 1578, Abbas' father became Shah of Iran. Abbas' mother soon came to dominate the government, but she had little time for Abbas, preferring to promote the interests of his elder brother Hamza. The queen antagonised leaders of the powerful Qizilbash army, who plotted against her and strangled her in July, 1579. Mohammed was a weak ruler who was incapable of preventing Iran's rivals, the Ottoman Empire and the Uzbeks, invading the country or stopping factional feuding among the Qizilbash. The young crown prince Hamza was more promising and led a campaign against the Ottomans, but he was murdered in mysterious circumstances in 1586. Attention now turned to Abbas.

At the age of 14, Abbas had come under the power of Murshid Qoli Khan, one of the leaders of the Qizilbash in Khorasan. When a large Uzbek army invaded Khorasan in 1587, Murshid decided the time was right to overthrow the ineffectual Shah Mohammed. He rode to the Safavid capital Qazvin with the young prince and proclaimed him king. The kingdom Abbas inherited was in a desperate state. The Ottomans had seized vast territories in the west and the north-west (including the major city of Tabriz) and the Uzbeks had overrun half of Khorasan in the north-east. Iran itself was riven by fighting between the various factions of the Qizilbash, who had mocked royal authority by killing the queen in 1579 and the grand vizier in 1583.

First, Abbas settled his score with his mother's killers, executing four of the ringleaders of the plot and exiling three others. His next task was to free himself from the power of the "kingmaker", Murshid Qoli Khan. Murshid made Abbas marry Hamza's widow and a Safavid cousin. He began distributing important government posts among his own friends. Gradually, he confined Abbas to the palace. Meanwhile the Uzbeks continued their conquest of Khorasan. Abbas heard they were besieging his old friend Ali Qoli Khan Shamlu in Herat and he pleaded with Murshid to take action. Fearing a rival, Murshid did nothing until the news came that Herat had fallen and the Uzbeks had slaughtered the entire population. Only then did he set out on campaign to Khorasan. But Abbas planned to avenge the death of Ali Qoli Khan and he suborned four Qizilbash leaders to kill Murshid after a banquet on 23 July 1589. Abbas could now rule Iran in his own right.

Abbas decided he must re-establish order within Iran before he took on the foreign invaders. To this end he made a humiliating peace treaty with the Ottomans in 1589/90, ceding them the provinces of Azerbaijan, Karabagh, Ganja and Qarajadagh as well as parts of Georgia, Luristanand Kurdistan. The Qizilbash had provided the backbone of the Iranian army from the very beginning of Safavid rule and they also occupied many posts in the government. To counterbalance their power, Abbas turned to another element in Iranian society, the ghulams (a word literally meaning "slaves"). These were Georgians, Armenians and Circassians who had converted to Islam and taken up service in the army or the administration. Abbas promoted such ghulams to the highest offices of the state. They included the Georgian Allahverdi Khan, who became leader of the ghulam regiments in the army as well as governor of the rich province of Fars. Abbas removed provincial governorships from some Qizilbash leaders and transferred Qizilbash groups to the lands of other Qizilbash tribes, thus weakening Qizilbash tribal unity. Budgetary problems were resolved by restoring the shah's control of the provinces formerly governed by the Qizilbash chiefs, the revenues of which supplemented the royal treasury.

Abbas needed to reform the army before he could hope to confront the Ottoman and Uzbek invaders. He also used military reorganisation as another way of sidelining the Qizilbash. Instead, he created a standing army of 40,000 ghulams and Iranians to fight alongside the traditional, feudal force provided by the Qizilbash. The new army regiments had no loyalty but to the shah. They consisted of 10,000-15,000 cavalry armed with muskets and other weapons, a corps of musketeers (12,000 strong) and one of artillery (also 12,000 strong). In addition Abbas had a personal bodyguard of 3,000 ghulams. Abbas also greatly increased the amount of cannons at his disposal, permitting him to field 500 in a single battle. Ruthless discipline was enforced and looting was severely punished. Abbas was also able to draw on foreign military advice, particularly from the brothers Anthony and Robert Shirley, who arrived in 1598 as envoys from the Earl of Essex to inquire about an anti-Ottoman alliance.

Abbas’ first campaign with his reformed army was against the Uzbeks who had seized Khorasan and were ravaging the province. In April, 1598 he went on the attack. One of the two main cities of the province, Mashhad, was easily recaptured. The Uzbek leader Din Mohammed Khan was safely behind the walls of the other chief city, Herat. Abbas managed to lure the Uzbek army out of the town by feigning a retreat. A bloody battle ensued on 9 August 1598, in the course of which the Uzbek khan was wounded and his troops retreated (the khan was murdered by his own men on the way).

Since the treaty of 1589-90 Abbas had been regarded as almost an Ottoman vassal. The Safavids had never beaten their western neighbours in a straight fight. In 1602, Abbas decided he would no longer put up with Ottoman insults. After a particularly arrogant series of demands from the Turkish ambassador, the shah had him seized, had his beard shaved and sent it to his master, the sultan, in Constantinople. This was a declaration of war. Abbas first recaptured Nahavand and destroyed the fortress in the city, which the Ottomans had planned to use as an advance base for attacks on Iran. The next year, Abbas pretended he was setting off on a hunting expedition to Mazandaran with his men. This was merely a ruse to deceive the Ottoman spies in his court - his real target was Azerbaijan. He changed course for Qazvin where he assembled a large army and set off to retake Tabriz, which had been in Ottoman hands for decades. For the first time, the Iranians made great use of their artillery and the town - which had been ruined by Ottoman occupation- soon fell. Abbas set off to besiege Yerevan, the capital of Armenia, and one of the main Turkish strongholds in the Caucasus. It finally fell in June 1604 and with it the Ottomans lost the loyalty of most Armenians, Georgians and other Caucasians. In 1605, Abbas sent his general Allahverdi Khan to meet Ottoman forces on the shores of Lake Van. On 6 November 1605 the Iranians led by Abbas scored a decisive victory over the Ottomans at Sufiyan, near Tabriz.

Several years of peace followed as the Ottomans carefully planned their response. But their secret training manoeuvres were observed by Iranian spies. Abbas learnt the Ottoman plan was to invade via Azerbaijan, take Tabriz then move on to Ardabil and Qazvin, which they could use as bargaining chips to exchange for other territories. The shah decided to lay a trap. He would allow the Ottomans to enter the country then destroy them. He had Tabriz evacuated of its inhabitants while he waited at Ardabil with his army. In 1618, an Ottoman army of 50,000 led by the grand vizier, invaded and easily seized Tabriz. The vizier sent an ambassador to the shah demanding he make peace and return the lands taken since 1602. Abbas refused and pretended he was ready to set fire to Ardabil and retreat further inland rather than face the Ottoman army. When the vizier heard the news, he decided to march on Ardabil right away. This was just what Abbas wanted. His army of 40,000 was hiding at a crossroads on the way and they ambushed the Ottoman army in a battle which ended in complete victory for the Iranians.

In 1623, Abbas decided to take back Mesopotamia which had been lost by his grandfather Tahmasp. Profiting from the confusion surrounding the accession of the new sultan Murad IV, he pretended to be making a pilgrimage to the Shi'ite shrines of Kerbala and Najaf but used his army to seize Baghdad. He was distracted by the rebellion in Georgia in 1624 which allowed an Ottoman force to besiege Baghdad, but the shah came to its relief the next year and crushed the Turkish army decisively. In 1638, however, after Abbas' death, the Ottomans retook Baghdad and the Iranian–Ottoman border became finalised.

Iran was traditionally allied with Mughal India against the Uzbeks, who coveted the province of Khorasan. The Mughal emperor Humayun had given Abbas’ grandfather, Shah Tahmasp, the province of Kandahar as a reward for helping him back to his throne. In 1590, profiting from the confusion in Iran, Humayun’s successor, Akbar, seized Kandahar. Abbas continued to maintain cordial relations with the Mughals, while always asking for the return of Kandahar. Finally, in 1620, a diplomatic incident in which the Iranian ambassador refused to bow down in front of the Emperor Jahangir led to war. India was embroiled in civil turmoil and Abbas found he only needed a lightning raid to take back Kandahar in 1622. After the conquest, he was very conciliatory to Jahangir, claiming he had only taken back what was rightly his and disavowing any further territorial ambitions. Jahangir was not appeased but he was unable to recapture the province.

During the 16th century the Portuguese had established bases in the Persian Gulf. In 1602, the Iranian army under the command of Imam-Quli Khan Undiladze managed to expel the Portuguese fromBahrain. In 1622, with the help of four English ships, Abbas retook Hormuz from the Portuguese in the Capture of Ormuz (1622). He replaced it as a trading centre with a new port, Bandar Abbas, nearby on the mainland, but it never became as successful.

Abbas moved his capital from Qazvin to the more central and more Persian Isfahan in 1598. Embellished by a magnificent series of new mosques, baths, colleges, and caravan sarais, Isfahan became one of the most beautiful cities in the world. Isfahan became the centre of Safavid architectural achievement. Abbas' painting ateliers (of the Isfahan school established under his patronage) created some of the finest art in modern Iranian history, by such illustrious painters as Reza Abbasi, Muhammad Qasim and others.

Like all other Safavid monarchs, Abbas was a Shi'ite Muslim. He had a particular veneration for Imam Hussein. In 1601, he made a pilgrimage on foot from Isfahan to Mashhad, site of the shrine of Imam Reza, which he restored (it had been despoiled by the Uzbeks). Since Sunni Islam was the religion of Iran's main rival, the Ottoman Empire, Abbas often treated Sunnis living in western border provinces harshly. Abbas was generally tolerant of Christianity. The Italian traveller Pietro della Valle was astonished at the shah's knowledge of Christian history and theology and establishing diplomatic links with European Christian states was a vital part of the shah's foreign policy. Christian Armenia was a key province on the border between Abbas' realm and the Ottoman Empire. From 1604 Abbas implemented a "scorched earth" policy in the region to protect his north-western frontier against any invading Ottoman forces, a policy which involved the forced resettlement of many Armenians from their homelands. Many were transferred to New Julfa, a town the shah had built for the Armenians near his capital Isfahan. Thousands of Armenians died on the journey. Those who survived enjoyed considerable religious freedom in New Julfa, where the shah built them a new cathedral. Other Armenians were transferred to the provinces ofGilan and Mazandaran. These were less lucky. Abbas wanted to establish a second capital in Mazandaran, Farahabad, but the climate was unhealthy and malarial. Many settlers died and others gradually abandoned the city. In 1614-15, Abbas suppressed a rebellion by the Christian Georgians of Kakheti, killing 60-70,000 and deporting over 100,000 Georgian peasants to Iran. He later had the Georgian queen Ketevan tortured to death when she refused to renounce Christianity.

Of Abbas' five sons, three had survived past childhood, so the Safavid succession seemed secure. He was on good terms with the crown prince, Mohammed Baqir Mirza (born 1587; better known in the West as Safi Mirza). In 1614, however, during a campaign in Georgia, the shah heard rumours that the prince was conspiring against his life with a leading Circassian, Fahrad Beg. Shortly after, Mohammed Baqir broke protocol during a hunt by killing a boar before the shah had chance to put his spear in. This seemed to confirm Abbas’ suspicions and he sunk into melancholy; he no longer trusted any of his three sons. In 1615, he decided he had no choice but to have Mohammed killed. A Circassian named Behbud Beg executed the Shah’s orders and the prince was murdered in ahammam in the city of Resht. The shah almost immediately regretted his action and was plunged into grief. In 1621, Abbas fell seriously ill. His heir, Mohammed Khodabanda, thought he was on his deathbed and began to celebrate his accession to the throne with his Qizilbash supporters. But the shah recovered and punished his son with blinding, which would disqualify him from ever taking the throne. The blinding was only partially successful and the prince’s followers planned to smuggle him out of the country to safety with the Great Mughal whose aid they would use to overthrow Abbas and install Mohammed on the throne. But the plot was betrayed, the prince’s followers were executed and the prince himself imprisoned in the fortress of Alamut where he would later be murdered by Abbas’ successor, Shah Safi. Imam Qoli Mirza, the third and last son, now became the crown prince. Abbas groomed him carefully for the throne but, for whatever reason, in 1627, he had him partially blinded and imprisoned in Alamut.

Unexpectedly, Abbas now chose as heir the son of Mohammed Baqir Mirza, Sam Mirza, a cruel and introverted character who was said to loathe his grandfather because of his father’s murder. It was he who in fact did succeed Shah Abbas at the age of seventeen in 1629, taking the name Shah Safi. Abbas’s health was troubled from 1621 onwards. He died at his palace in Mazandaran in 1629 and was buried in Kashan.