809 - 813 GREAT ABBASID CIVIL WAR (Persia)
Also knows as the Forth Fitna, broke out between the sons of Al Rashid - Mohammed Alemin and Abdulla Almamun. The war entailed severe persecution for non-Moslems. With Alemin's defeat, Almamun became the caliph. His reign (813-833) was marked by tolerance and the development of a philosophical form and scientific study.founded an academy called the House of Wisdom (Bayt al-Ḥikmah).