During this period, Shia in Iran were nourished from Kufah, Baghdad and later from Najaf and Hillah. However, during the first nine centuries there are four high points in the history of this linkage: First, the migration of a number of persons belonging to the tribe of the Ash'ari from Iraq to the city of Qum towards the end of the first/seventh century, which is the period of establishment of Imamī Shī‘ism in Iran. Second, the influence of the Shī‘ī tradition of Baghdad and Najaf on Iran during the fifth/eleventh and sixth/twelfth centuries. Third, the influence of the school of Hillah on Iran during the eighth/fourteenth century. Fourth, the influence of the Shī‘ism of Jabal Amel and Bahrain on Iran during the period of establishment of the Safavid rule. Shi'ism and the Safavids Due to their history being almost fully intertwined, Iran as well as Azerbaijan are both discussed here. Iran and Azerbaijan were predominantly Sunni until the 16th century. Changes in the religious make-up of nowadays both nations changed drastically from that time and on. In 1500 the Safavid Shah Ismail I undertook the conquering of Iran and Azerbaijan and commenced a policy of forced conversion of Sunni Muslims to Shia Islam. Many Sunnis were murdered. When Shah Ismail I conquered Iraq, Dagestan, Eastern Anatolia, and Armenia he similarly forcefully converted or murdered Sunni Muslims. The oppression and forced conversion of Sunnis would continue, mostly unabated, for the greater part of next two centuries until Iran as well as what is now Azerbaijan became predominantly Shi’ite countries. As in the case of the early caliphate, Safavid rule had been based originally on both political and religious legitimacy, with the shah being both king and divine representative. With the later erosion of Safavid central political authority in the mid-17th century, the power of the Shia scholars in civil affairs such as judges, administrators, and court functionaries, began to grow, in a way unprecedented in Shi'ite history. Likewise, the ulama began to take a more active role in agitating against Sufism and other forms of popular religion, which remained strong in Iran, and in enforcing a more scholarly type of Shi'a Islam among the masses. The development of the ta'ziah—a passion play commemorating the martyrdom of Imam Husayn and his family — and Ziarat of the shrines and tombs of local Shi'ite leaders began during this period, largely at the prompting