The First Fitna was the first civil war in the Islamic community which led to the overthrow of the Rashidun Caliphate and the establishment of the Umayyad Caliphate. The civil war involved three main battles between the fourth Rashidun caliph, Ali, and the rebel groups. The roots of the first civil war can be traced back to the assassination of the second caliph, Umar. Before he died from his wounds, Umar formed a six-member council, which ultimately elected Uthman as the next caliph. During the final years of Uthman's caliphate, he was accused of nepotism and eventually killed by rebels in 656. After Uthman's assassination, Ali was elected the fourth caliph. Aisha, Talha, and Zubayr revolted against Ali to depose him. The two parties fought the Battle of the Camel in December 656, in which Ali emerged victorious. Afterwards, Mu'awiya, the incumbent governor of Syria, declared war on Ali ostensibly to avenge Uthman's death. The two parties fought the Battle of Siffin in July 657.