Safavid conversion of Iran to Shia Islam

The Safavid conversion of Iran from Sunnism to Shiism took place roughly over the 16th through 18th centuries and made Iran the spiritual bastion of Shia Islam against the onslaughts of Sunni Islam. It made Iran the repository of Persian cultural traditions and self-awareness of Iranianhood, acting as a bridge to modern Iran. It also ensured the dominance of the Twelver sect within Shiism over the Zaydiyyah and Ismaili sects – each of whom had previously experienced their own eras of dominance within Shiism. Through their actions, the Safavids reunified Iran as an independent state in 1501 and established Twelver Shiism as the official religion of their empire, marking one of the most important turning points in the history of Islam.

As a direct result, the population of the territory of present-day Iran and neighbouring Azerbaijan were converted to Shia Islam at the same time in history. Both nations still have large Shia majorities, and the Shia percentage of Azerbaijan's population is second only to that in Iran.

Iran’s population was mostly Sunni of the Shafi`i and Hanafi legal rites until the triumph of the Safavids (who had initially been Shafi`i Sufis themselves). Ironically, this was to the extent that up until the end of the 15th century the Ottoman Empire (the most powerful and prominent Sunni state and future arch-enemy of the Shia Safavids) used to send many of its Ulama (Islamic scholars) to Iran to further their education in Sunni Islam, due to a lack of Madrasahs (Islamic schools) within the Empire itself. The Sunni Iranians had always held the family of Muhammad in high esteem. In contrast, before the Safavid period, a minority of Iranians were Shia and there had been relatively few Shia Ulama in Iran.

From 1500–2 Ismail I conquered Tabriz in Iran, as well as Armenia, Azerbaijan, and parts of Dagestan (North Caucasus, nowadays part of Russia). He would take most of the next decade to consolidate his control over Iran, where most of the Persian population was still Sunni. His army spread out first to the central regions in 1504. He captured southwestern Iran between 1505 and 1508 before finally conquering the Khorasan region and the city of Herat in 1510. According to Daniel W. Brown, Isma'il was "the most successful and intolerant Shi'i ruler since the fall of the Fatimids". It appears that he aimed for complete destruction of Sunni Islam, and he largely achieved that goal in the lands over which he ruled. He required the first three caliphs to be ritually cursed, abolished Sunni Sufi orders, seizing their property, and gave Sunni ulama a choice of conversion, death, or exile. Shi'i scholars were brought in from other regions to take their place.

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