Al-Ma'mun
During his reign al-Ma’mun tried to reunite Sunnis and Shiites. These are the two main brances of Islam that have different beliefs on who should lead Islam. Al-Ma’mun opened many learning centers in his empire. One big one was in Baghdad, which was called the House of Wisdom. Many other libraries and schools were built all over the empire. He was also a big sponsor of philosophy and astronomy.