The First Islamic Civil War, also called the First Fitna, the first major civil war within the Islamic Empire, arises as a disagreement over who has the legitimate right to occupy the position of Caliph.

It results in large divisions within the Muslim community, and is regretted as the end of the early unity of the Muslim ummah.Essentially, it is a series of revolts fought against Ali ibn Abi Talib, the fourth Rashidun caliph, caused by the controversial assassination of his predecessor, Uthman Ibn Affan.

It lasts for the entirety of Ali's reign, and its end is marked by Muawiyah's assumption of the caliphate and the subsequent peace treaty between him and Hassan ibn Ali.