The First Islamic Civil War (656–661), also called the First Fitna (Arabic: فتنة مقتل عثمان, Transliteration: Fitnat Maqtal Uthmān "The Fitna of the killing of Uthman"), was the first major civil war within the Islamic Caliphate. It arose as a result of the death of the previous Caliph Uthman.
The Fitna began as a series of revolts fought against Ali ibn Abi Talib, the fourth and final of the Sunni Rightly Guided Caliphs and first Imam of Shia'a. It was caused by the controversial assassination of his predecessor, Uthman Ibn Affan. It lasted for the entirety of Ali's reign, and its end is marked by Muawiyah's assumption of the caliphate (founding the Umayyad dynasty), and the subsequent recorded peace treaty between him and Hassan ibn Ali.
Read more about First Fitna: Background, Battle of The Camel, Battle of Siffin, Arbitration, Battle of Nahrawan, Loss of All Provinces Except Kufa, Last Days of Ali, Hasan Caliphate