Nader Shah was born in Dastgerd into the Qereqlu clan of the Afshars, a semi-nomadic tribe in Khorasan, a province in the north-east of the Persian Empire. His father, a poor peasant, died while Nader was still a child. According to legends, Nader and his mother were carried off as slaves by marauding Uzbek or Turkmen tribesmen, but Nader managed to escape. He joined a band of brigands while still a boy and eventually became their leader. Under the patronage of Afshar chieftains, he rose through the ranks to become a powerful military figure. Nader married the two daughters of Baba Ali Beg, a local chief.
Tahmasp and the Qajar leader Fath Ali Khan (the ancestor of Agha Mohammad Khan Qajar) contacted Nader and asked him to join their cause and drive the Afghans out of Khorasan. He agreed and thus became a figure of national importance. When Nader discovered that Fath Ali Khan was in treacherous correspondence with Malek Mahmud and revealed this to the shah, Tahmasp executed him and made Nader the chief of his army instead. Nader subsequently took on the title Tahmasp Qoli (Servant of Tahmasp). In late 1726, Nader recaptured Mashhad.
Nader chose not to march directly on Isfahan. First, in May 1729, he defeated the Abdali Afghans near Herat. Many of the Abdali Afghans subsequently joined his army. The new Ghilzai Afghan shah, Ashraf, decided to move against Nader but in September 1729, Nader defeated him at the Battle of Damghan and again, decisively, in November at Murchakhor. Ashraf fled and Nader finally entered Isfahan, handing it over to Tahmasp in December. The citizens' rejoicing was cut short when Nader plundered them to pay his army. Tahmasp made Nader governor over many eastern provinces, including his native Khorasan, and married him to his sister. Nader pursued and defeated Ashraf, who was murdered by his own followers. In 1738 Nader Shah besieged and destroyed Kandahar. This was the ultimate defeat of any remaining Afghan forces. Nader Shah built a new city near Kandahar, which he named Naderabad.
Relations between Nader and the Shah had declined as the latter grew jealous of his general's military successes. While Nader was absent in the east, Tahmasp tried to assert himself by launching a foolhardy campaign to recapture Yerevan. He ended up losing all of Nader’s recent gains to the Ottomans, and signed a treaty ceding Georgia and Armenia in exchange for Tabriz. Nader saw that the moment had come to ease Tahmasp from power. He denounced the treaty, seeking popular support for a war against the Ottomans. In Isfahan, Nader got Tahmasp drunk then showed him to the courtiers asking if a man in such a state was fit to rule. In 1732 he forced Tahmasp to abdicate in favor of the Shah’s baby son, Abbas III, to whom Nader became regent.
Nader decided he could win back the territory in Armenia and Georgia by seizing Ottoman Baghdad and then offering it in exchange for the lost provinces, but his plan went badly amiss when his army was routed by the Ottoman general Topal Osman Pasha near the city in 1733. Nader decided he needed to regain the initiative as soon as possible to save his position because revolts were already breaking out in Persia. He faced Topal again with a larger force and defeated and killed him. He then besieged Baghdad, as well as Ganja in the northern provinces, earning a Russian alliance against the Ottomans. Nader scored a great victory over a superior Ottoman force at Baghavard and by the summer of 1735, Persian Armenia and Georgia were his again. In March 1735, he signed a treaty with the Russians in Ganja by which the latter agreed to withdraw all of their troops from Persian territory.
In 1738, Nader Shah conquered Kandahar, the last outpost of the Ghilzai Afghans. His thoughts now turned to Mughal India to the south. This once powerful Muslim state was falling apart as the nobles became increasingly disobedient and the Hindu Marathas made inroads on its territory from the south-west. Its ruler Mohammed Shah was powerless to reverse this disintegration. Nader used the pretext of his Afghan enemies taking refuge in India to cross the border and capture Kabul, Ghazni and Lahore. He then advanced deeper into India crossing the river Indus before the end of year. He defeated the Mughal army at the huge Battle of Karnal in February, 1739. After this victory, Nader captured Mohammad Shah and entered with him into Delhi. When a rumour broke out that Nader had been assassinated, some of the Indians attacked and killed Persian troops. Nader reacted by ordering his soldiers to massacre the population and plunder the city. During the course of one day (March 22) 20,000 to 30,000 Indians were killed by the Persian troops, forcing Mohammad Shah to beg for mercy. In response, Nader Shah agreed to withdraw, but Mohammad Shah paid the consequence in handing over the keys of his royal treasury, and losing even the Peacock Throne to the Persian emperor. The Peacock Throne thereafter served as a symbol of Persian imperial might. Among a trove of other fabulous jewels, Nader also gained the Koh-i-Noor and Darya-ye Noor diamonds (Koh-i-Noor means "Mountain of Light" in Persian, Darya-ye Noor means "Sea of Light"). The Persian troops left Delhi at the beginning of May 1739. Nader's soldiers also took with them thousands of elephants, horses and camels, loaded with the booty they had collected. The plunder seized from India was so rich that Nader stopped taxation in Iran for a period of three years following his return.
The Indian campaign was the zenith of Nader's career. Afterwards he became increasingly despotic as his health declined markedly. Nader had left his son Reza Qoli Mirza to rule Persia in his absence. Reza had behaved highhandedly and somewhat cruelly but he had kept the peace in Persia. Having heard rumours that his father had died, he had made preparations for assuming the crown. These included the murder of the former shah Tahmasp and his family, including the nine-year old Abbas III. On hearing the news, Reza’s wife, who was Tahmasp’s sister, committed suicide. Nader was not impressed with his son’s waywardness and reprimanded him, but he took him on his expedition to conquer territory in Transoxiana. After the Persians had forced the Uzbek khanate of Bokhara to submit, Nader wanted Reza to marry the khan’s elder daughter because she was a descendant of his hero Genghis Khan, but Reza flatly refused and Nader married the girl himself. Nader also conquered Khwarezm on this expedition into Central Asia.
Nader now decided to punish Daghestan for the death of his brother Ebrahim Qoli on a campaign a few years earlier. In 1741, while Nader was passing through the forest of Mazanderan on his way to fight the Daghestanis, an assassin took a shot at him but Nader was only lightly wounded. He began to suspect his son was behind the attempt and confined him to Tehran. Nader’s increasing ill health made his temper ever worse. Perhaps it was his illness that made Nader lose the initiative in his war against the Lezgin tribes of Daghestan. Frustratingly for him, they resorted to guerrilla warfare and the Persians could make little headway against them. Nader accused his son of being behind the assassination attempt in Mazanderan. Reza angrily protested his innocence, but Nader had him blinded as punishment, although he immediately regretted it. Soon afterwards, Nader started executing the nobles who had witnessed his son's blinding. In his last years, Nader became increasingly paranoid, ordering the assassination of large numbers of suspected enemies.
With the wealth he gained from India, Nader started to build a Persian navy. With lumber from Mazandaran, he built ships in Bushehr. He also purchased thirty ships in India. He recaptured the island of Bahrain from the Arabs. In 1743 he conquered Oman and its main capital the city of Muscat. In 1743 Nader started another war against the Ottoman Empire. Despite having a huge army at his disposal, in this campaign Nader showed little of his former military brilliance. It ended in 1746 with the signing of a peace treaty, in which the Ottomans agreed to let Nader occupy Najaf.
Nader changed the Iranian coinage system. He minted silver coins, called Naderi, that were equal to the Mughal rupee. Nader discontinued the policy of paying soldiers based on land tenure. Like the late Safavids he resettled tribes. Nader Shah transformed the Shahsevan, a nomadic group living around Azerbaijan whose name literally means "shah lover", into a tribal confederacy which defended Iran against the Ottomans and Russians. In addition, he increased the number of soldiers under his command and reduced the number of soldiers under tribal and provincial control. His reforms may have strengthened the country, but they did little to improve Iran's suffering economy.
Nader became crueller and crueller as a result of his illness and his desire to extort more and more tax money to pay for his military campaigns. More and more revolts broke out and Nader crushed them ruthlessly, building towers from his victims’ skulls in imitation of his hero Timur. In 1747, Nader set off for Khorasan where he intended to punish Kurdish rebels. Some of his officers feared he was about to execute them and plotted against him. Nader Shah was assassinated on 19 June, 1747, at Fathabad in Khorasan. He was surprised in his sleep by Salah Bey, captain of the guards, and stabbed with a sword. Nader was able to kill two of the assassins before he died.
After his death, he was succeeded by his nephew Ali Qoli, who renamed himself Adil Shah ("righteous king"). Adil Shah was probably involved in the assassination plot. Adil Shah was deposed within a year. During the struggle between Adil Shah, his brother Ibrahim Khan and Nader's grandson Shah Rukh almost all provincial governors declared independence, established their own states, and the entire Empire of Nader Shah fell into anarchy. Finally, Karim Khan founded the Zand dynasty and became ruler of Iran by 1760, while Ahmad Shah Durrani had already proclaimed independence in the east, marking the foundation of modern Afghanistan.
Nader Shah was well known to the European public of the time. In 1768, Christian VII of Denmark commissioned Sir William Jones to translate a Persian language biography of Nader Shah written by his Minister Mirza Mehdi Khan Astarabadi into French. It was published in 1770 as Histoire de Nadir Chah. Nader's Indian campaign alerted the British East India Company to the extreme weakness of the Mughal Empire and the possibility of expanding to fill the power vacuum. Without Nader, "eventual British rule [in India] would have come later and in a different form, perhaps never at all - with important global effects".
