The First Islamic Civil War (656–661), also called the First Fitna (), was the first major Fitna within the Fitna. It arose as a struggle over who had the legitimate right to become the ruling Fitna. The dispute shattered the unity of the Muslim Fitna and resulted in the permanent division of Islam into rival Fitna and Fitna sects.
The Fitna began as a series of revolts fought against Fitna, the fourth and final of the so-called Fitna, caused by the controversial assassination of his predecessor, Fitna. It lasted for the entirety of Ali's reign, and its end is marked by Fitna's assumption of the caliphate (founding the Fitna), and the subsequent peace treaty between him and Fitna.
Battle of Bassorah
Ali was first opposed by a faction led by Talhah, Al-Zubayr and the Muhammad's wife, Fitna bint Abu Bakr. This group was known as disobedients (Nakithin) by their enemies. First they gathered in Mecca then moved to Fitna with the expectation of finding the necessary forces and resources to mobilize people in what is now Iraq. The rebels occupied Basra, killing many people. When Ali asked them for obedience and a pledge of allegiance, they refused. The two parties met at the Fitna (Battle of the Camel) in 656, where Ali emerged victorious.
Battle of Siffin
Later Ali was challenged by Fitna, the governor of Fitna and the cousin of Fitna, who refused Ali's demands for allegiance and called for revenge for Uthman. Ali opened negotiations with him with the hope of regaining his allegiance but Muawiyah insisted on Levant autonomy under his rule. Muawiyah replied by mobilizing his Fitnan supporters and refusing to pay homage to Ali on the pretext that his contingent had not participated in his election. The two armies encamped themselves at Fitna for more than one hundred days, most of the time being spent in negotiations. Although Ali exchanged several letters with Muawiyah, he was unable to dismiss the latter, nor persuade him to pledge allegiance. Skirmishes between the parties led to the Fitna in 657. After a week of combat was followed by a violent battle known as laylat al-harir (the night of clamor) the Muawiyah's army were on the point of being routed when Fitna advised Muawiyah to have his soldiers hoist Fitna (then parchments inscribed with verses of the Qur'an) on their spearheads in order to cause disagreement and confusion in Ali's army.
The two armies finally agreed to settle the matter of who should be Caliph by arbitration. The refusal of the largest bloc in Ali's army to fight was the decisive factor in his acceptance of the arbitration. The question as to whether the arbiter would represent Ali or the Fitna caused a further split in Ali's army. Fitna and some others rejected Ali's nominees, Fitna and Fitna, and insisted on Fitna, who was opposed by Ali, since he had earlier prevented people from supporting him. Finally Ali was urged to accept Abu Musa.
Battle of Nahrawan
Some of Ali's supporters, later were known as Fitna (Fitnatics), opposed this decision and rebelled and Ali had to fight with them in the Fitna. The arbitration resulted in the dissolution of Ali's coalition.
Loss of All Provinces Except Kufa
Muawiyah's army invaded and occupied cities, which Ali's governors couldn't prevent and people didn't support him to fight with them. Muawiyah overpowered Egypt, Yemen and other areas.
Last days of Ali
On the nineteenth of Ramadan, while Ali was praying in the mosque of Kufa, the Fitna Fitna assassinated him with a strike of his poison-coated sword. Ali, wounded by the poisonous sword, lived for two days and died on the 21st of Ramadan in the city of Kufa in 661 A.D.
Upon the death of Ali ibn Abi Talib, Kufi Muslims pledged allegiance to his eldest son Fitna without dispute.