of antagonism between the two groups. Initial dependence of Shīʿīte clerics on the state followed by the emergence of an independent body of ulama capable of taking a political stand different from official policies. The growth in importance of Persian centers of Islamic education and religious learning, which resulted in the change of Twelver Shīʿīsm from being a predominantly Arab phenomenon to become predominantly Persian. The growth of the Akhbari school of thought, which taught that only the Quran, ḥadīth literature, and sunnah (accounts of the sayings and living habits attributed to the Islamic prophet Muhammad during his lifetime) are to be bases for verdicts, rejecting the use of reasoning. With the fall of the Safavids, the state in Persia—including the state system of courts with government-appointed judges (qāḍī)—became much weaker. This gave the sharīʿa courts of mujtahid an opportunity to fill the legal vacuum and enabled the ulama to assert their judicial authority. The Usuli school of thought also increased in strength at this time. Persecution of Shīʿa Muslims The history of Shīʿa—Sunnī relations has often involved religious discrimination, persecution, and violence, dating back to the earliest development of the two competing sects. At various times throughout the history of Islam, Shīʿa groups and minorities have faced persecution perpetrated by Sunnī Muslims. Militarily established and holding control over the Umayyad government, many Sunnī rulers perceived the Shīʿas as a threat—both to their political and religious authority. The Sunnī rulers under the Umayyad dynasty sought to marginalize the Shīʿa minority, and later the Abbasids turned on their Shīʿa allies and imprisoned, persecuted, and killed them. The persecution of Shīʿa Muslims throughout history by their Sunnī co-religionists has often been characterized by brutal and genocidal acts. Comprising only about 10–15% of the global Muslim population, Shīʿa Muslims remain a marginalized community to this day in many Sunnī-dominant Arab countries, without the rights to practice their religion and freely organize. In 1514, the Ottoman sultan Selim I (1512–1520) ordered the massacre of 40,000 Alevis and Bektashi (Anatolian Shīʿa Muslims). According to Jalal Al-e-Ahmad, "Sultan Selim I carried things so far that he announced that the killing of one Shīʿa had as much otherworldly reward as killing 70 Christians." In 1802, the Al Saud-Wahhabi armies of the Ikhwan from the First Saudi State (1727–1818) attacked and sacked the city of Karbala, the Shīʿa shrine in Najaf (eastern region of Iraq) that commemorates the