The First Fitna (Arabic: الفتنة الكبرى) was the first civil war in the Islamic community. It led to the end of the Rashidun Caliphate and the establishment of the Umayyad Caliphate. The civil war involved three main factions; the supporters of the fourth Rashidun caliph Ali, the Uthmaniyya (partisans of the slain caliph Uthman led primarily by Aisha and Mu'awiya I), and the Kharijites, a faction of radical secessionists who broke away from Ali's camp following the arbitration at Siffin.
The roots of the first civil war can be traced back to the assassination of the second Rashidun caliph, Umar. Before he died from his wounds, Umar formed a six-member council which elected Uthman as the next caliph. During the final years of Uthman's caliphate, he was accused of nepotism and killed by rebels in 656. After Uthman's assassination, Ali was elected the fourth caliph, though his accession was immediately clouded by the unresolved murder of his predecessor. Aisha, Talha, and Zubayr represented the initial opposition to Ali's rule. They argued that Ali had failed to prioritize the prosecution of Uthman's killers and revolted to demand a new elective council. The two parties fought the Battle of the Camel in December 656, from which Ali emerged victorious. Afterwards, Mu'awiya, the long-time governor of the Levant and a kinsman of Uthman, also refused to recognize Ali as caliph. He declared war on the basis of his right to seek blood-revenge for his cousin. The two parties fought the Battle of Siffin in July 657, which ended in a stalemate and arbitration.
This arbitration was resented by the Kharijites, who declared Ali, Mu'awiya, and their followers to be infidels. Following Kharijite violence against civilians, Ali's forces crushed them in the Battle of Nahrawan. Soon after, Mu'awiya also seized control of Egypt with the aid of Amr ibn al-As.
In 661, Ali was assassinated by the Kharijite Abd al-Rahman ibn Muljam. After Ali's death, his eldest son Hasan was acclaimed as his successor in Kufa. Mu'awiya quickly marched on Kufa with a large army. The embattled Hasan concluded a peace treaty, acknowledging the rule of Mu'awiya, who subsequently founded the Umayyad Caliphate and ruled as its first caliph.
Following Muhammad's death in 632, Abu Bakr became the leader of the Muslim community. After reasserting Muslim control over the dissident tribes of Arabia, he sent armies to fight against the empires of Byzantium and Sasanian Persia, initiating a wave of conquests which were continued by his successor Umar (r. 634–644). These battles brought about the near-total collapse of the Sasanians, and restricted the Byzantine Empire to Anatolia, North Africa, and its holdings in Europe. The conquests brought Muslims bounteous revenue and lands. In Iraq, the lands of the Persian crown and aristocracy were now in Muslim hands. These became state-administered communal property. The revenue was distributed among the conquering troops, who settled in Iraq. Umar also left provincial administration to regional governors, who ruled with considerable autonomy. Provincial surplus was spent on the Muslim settlers of the conquered territories rather than forwarded to the capital at Medina.
Uthman succeeded Umar upon the latter's assassination by a slave in 644. The new caliph's policies elicited discontent among the Muslim elite as well as accusations of nepotism. He began centralizing power by relying on his Umayyad relatives, who had long opposed Muhammad before converting to Islam in 630. His favor toward relatives was to the exclusion of other members of the Quraysh, who had enjoyed significant authority during the reign of his two predecessors. He appointed his kinsmen to nearly all of the important provincial governorships. Although Uthman continued Muslim expansion in Persia and Egypt, these conquests came to a halt by the latter half of his reign. The influx of spoils slowed, magnifying economic issues that had previously been tempered by incoming revenue. This was coupled with the antipathy of the Arab nomads towards central authority, which had hitherto been superseded by the continued war effort. The continued migration of Arab tribes from the Peninsula to the conquered territories also resulted in reduced payments from the revenue of the lands, which led to resentment among the earlier settlers. Early settlers also saw their status threatened by land grants in the conquered territories to prominent Qurayshites like Talha ibn Ubayd Allah and Zubayr ibn al-Awwam, as well as land acquisitions by late-arriving tribal chiefs, such as Al-Ash'ath ibn Qays. These chiefs were given this territory in exchange for their lands in Arabia. Furthermore, Uthman took control of the crown lands of Iraq as state assets and demanded that the provincial surplus be forwarded to the caliph. This interference in provincial affairs brought about widespread opposition to his rule, especially from Iraq and Egypt, where the majority of the conquering armies had settled.
Encouraged by the disaffected Muslim elite in Medina including prominent figures like Talha, Zubayr, Amr ibn al-As (the conqueror and former governor of Egypt who Uthman deposed in favour of his foster brother), and Muhammad's wife Aisha, the provincial opposition subsequently broadened into open rebellion. Dissidents from Egypt and Iraq marched on Medina, killing the caliph in June 656. Ali, Muhammad's cousin and son-in-law, was subsequently recognized caliph.
Aisha, Talha, and Zubayr opposed Ali's succession and gathered in Mecca, where they demanded vengeance for Uthman's death and the election of a new caliph, presumably Talha. The rebels raised an army and captured Basra from Ali's governor, inflicting heavy casualties on his men, with the intention of strengthening their position. Ali sent his son Hasan to mobilize troops in Kufa. After Ali arrived in Kufa himself, the combined army marched to Basra.
The two armies met outside Basra. After three days of failed negotiations, the battle began in the afternoon of 8 December 656 and lasted until the evening. Zubayr left the field without fighting. Likely for the dishonorable act of leaving his fellow Muslims behind in a civil war he caused, Zubayr was pursued and killed shortly thereafter by Amr ibn Jarmuz, a man from the troops of al-Ahnaf bin Qays, a chief of the Banu Sa'd who had remained on the sidelines of the battle. Talha was killed by Marwan ibn al-Hakam, who was a kinsman and former secretary of Uthman, and a member of the Umayyad clan.
With the deaths of Talha and Zubayr, the fate of the battle was sealed in favor of Ali. However, the fight continued until Ali's troops succeeded in killing Aisha's camel, which her forces had rallied around. From this camel, the battle received its name. After admonishing Aisha, Ali sent her back to Medina, escorted by her brother. Ali also announced a public pardon and set the prisoners free. This pardon was also extended to high-profile rebels, including Marwan, who soon joined with his Umayyad kinsman Mu'awiya ibn Abi Sufyan, the long-time governor of Greater Syria, as a senior advisor.
Shortly after assuming power, Ali dismissed most governors whom he considered corrupt, including Mu'awiya, Uthman's cousin. Mu'awiya refused to step down and informed Ali through a representative that he would recognize Ali as caliph in exchange for the continued governorship of Syria, and possibly the annexation of Egypt. Ali rejected this proposal.
In response, Mu'awiya declared war on Ali on behalf of the Syrians, demanding vengeance for Uthman's death. The governor of Syria aimed to depose Ali and establish a new council in Syria to appoint the next caliph, who would presumably be Mu'awiya himself. Ali responded by letter that Mu'awiya was welcome to bring his case to Ali's court of justice, asking him to offer any evidence that would incriminate Ali in the murder of Uthman. Ali also challenged Mu'awiya to name any Syrian who would qualify for a new council.