Ali, the fourth caliph, with his sons and successors Hasan ibn Ali and Husain ibn Ali. Persian miniature, 1837 • ROLAND AND SABRINA MICHAUD / AKG In inaugurating the Safavid dynasty, which reigned until 1736, Ismail I st (1501-1524), the mystical “blue-eyed shah”, made the first strong gesture of declaring Shiism the official religion of his entire empire. Does he suspect then that his decision will seal a lasting union between religion and politics, at the same time as it will anchor the Iranian difference in a predominantly Sunni Muslim world, dominated in the east by the Ottoman Empire, and in the west, by the Uzbeks? The reasons for a split To fully understand this choice with lasting consequences, it is useful to recall the reasons for the split between Sunnism and Shiism. During the Islamization of the Middle East by Muhammad in the 7th th century, all the inhabitants, Arabs or not, are united, willingly or by force, under the banner of a single Islam. When the Prophet died in 632, the hegemonic appetites of the clans, over a territory that stretched from Egypt to Arabia, reawakened. Four caliphs, called the "Rightly Guided" (rashidun ), one after the other. The first, Abu Bakr, companion of the Prophet, died of illness in 634. The next two were assassinated:Omar in 644, then Othman in 656. The fourth, Ali, husband of Fatima, daughter of the Prophet, was deposed in 659 by Moawiya , Governor of Damascus. This deposition marks the split of Muslims between Sunnis and Shiites. Indeed, with the seizure of power by Moawiya (661-680), first caliph of the Umayyad dynasty (661-750), two factions clashed:one Sunni, majority, which recognized the Umayyads; the other Shia, a minority, who disputes them. For the latter, Ali is the natural successor of Muhammad, this privilege extending to his descendants. However, after the assassination of Ali in 661 and the Shiite defeat of Karbala in 680, during which Ali's son and his successor Hussein were killed, his family, pursued by the Sunni power of Damascus, took refuge in Iran. . This is how, in this country, the birth of a strong partisan movement of Ali, Shiism (from the Arabic chi’a , "gone"). Iranian Shiism is based on the belief in the twelve imams. The series of imams was interrupted in 873 by the disappearance (the “occultation”) of Muhammad, the twelfth imam still alive, but hidden, who must reappear one day to bring peace and justice to earth. He is the mahdi, the hidden Imam, or the Master of time. Mark your difference For its part, Sunnism, the majority in the current Muslim world, follows the message of the Koran and that of the Sunna, that is to say the tradition collected in the hadiths, where the oral communications of the Prophet and his companions. The imam is not a guide as in Shiism, but a reader and commentator of the Koran. Many years later, in the 16 th century, the accession to the throne of Shah Ismail, first of the Safavids, resulted from this situation, but also from the rise of a spiritual movement born in the 12 th century. During this troubled time, a mentor, Sheikh Zahed Gilani, attracted a growing group of Sufis around him. Sufism, suspect in rigorous Muslim circles, professes asceticism and renunciation of the world, personal elevation towards the love of God. A brilliant disciple of the master, Safi al-Din, marries his daughter, before taking the head of the circle, which soon becomes the order safavieh (Safavid). Zahed being a Shiite, the Safavids relate to Shiism. If the spiritual stakes occupy them, soon a hegemonic desire is grafted to it. It culminates with the coronation of Ismail I st , for whom Shiism, the state religion, constitutes a double strategic lever:a tool for bringing together all Iranians, it is also a strong political mark of their differences with respect to their neighbours, the Ottomans and Uzbeks, mostly Sunnis. The conversion to Shiism of many Iranians may have been violent. Indeed, in some border regions, in Tabriz for example, Sunnism dominates under the influence of successive masters (caliphs of Baghdad, Seljuks and Turco-Mongols), hence a fierce resistance. It is therefore sometimes at the cost of certain cruelty, but also of an education in Shiism, that Ismail will unite his peoples under the same religious banner. A declaration of war On a more political level, Ismaïl clearly understood that the Sultan of the Sublime Porte, Selim I er (1512-1520), his hereditary enemy, wanted to unify the Islamic world – including Iran – under his Sunni banner. The Shiite choice of the Safavid therefore resonates like a declaration of war, especially since, in a few years, the Iranians have nibbled away at territories under Ottoman and Uzbek domination, and regained the borders of the Sassanid Empire of the 6th century. century, before the Arab conquest. If the Uzbeks are quickly pushed back, it is not the same for the Ottomans. Selim I er begins by ordering the massacre of 400,000 Shiites living in his states. Then he attacks Iranian territory. On August 22, 1514, in Tchaldiran, it is the confrontation. “We will all win or die on the spot,” proclaims Ismail. On the evening of August 23, the Iranian defeat was total. This defeat, the Iranians will soon convert it into a founding act of their nation, into an apotheosis of supreme sacrifice in the face of an impious enemy, exalting Shiism as the politico-religious asset of their difference.