The First Fitna or First Islamic Civil War was a civil war within the early Islamic state which resulted in the overthrowing of the Rashidun caliphs and the establishment of the Umayyad dynasty. It began when the caliph Uthman ibn Affan was assassinated by Egyptian rebels in 656 and continued through the four-year reign of Uthman's successor Ali ibn Abi Talib. It ended in 661 when Ali's heir Hasan ibn Ali concluded a treaty acknowledging the rule of Muawiyah, the first Umayyad caliph.