Upon the death of the Prophet in 632, ʿAlī and Muhammad’s family took charge of the arrangements for his funeral. At the same time, discussions began concerning who should succeed Muhammad. Both the anṣār, the people of Medina who had embraced Islam, and the muhājirūn, those from Mecca who had migrated to Medina, wanted the successor to come from their group. In order to avoid division, the leaders of the community assembled at saqīfat Banī Sāʿidah (“the room with the thatched roof of the tribe of Banī Sāʿidah”) to choose a successor. After much debate, Abū Bakr was named caliph (khalīfah, “successor”), the ruler of the Islamic community. By the time ʿAlī finished with matters pertaining to the funeral of the Prophet, he was presented with a fait accompli. He did not protest but retired from public life and dedicated himself to studying and teaching the Qurʾān. He was often consulted, however, by Abū Bakr and his successor, ʿUmar, in matters of state.

After the death of ʿUmar in 644, ʿAlī was considered for the caliphate along with five other eminent members of the community. One of them, ʿAbd al-Raḥmān ibn ʿAwf, withdrew but asked that he be trusted with choosing the next caliph, a request that was granted. He questioned both ʿUthmān and ʿAlī and decided in favour of the former. ʿAlī recognized the caliph’s authority, according to Shiʿi sources, but remained neutral between ʿUthmān’s supporters and his opponents. ʿAlī even sent his own sons to protect ʿUthmān’s house when he was in danger of being attacked. When ʿUthmān was murdered in 656 by those who considered him weak and who accused him of nepotism, ʿAlī admonished his children for not having defended ʿUthmān’s house properly. ʿAlī himself was then chosen as the fourth and last of the rightly guided caliphs.

ʿAlī’s caliphate and last years

The period of the caliphate of ʿAlī, from 656 until his death in 661, was the most tumultuous in his life. Many members of the Quraysh turned against him because he defended the rights of the Hashemites, a clan of the Quraysh to which Muhammad had belonged. He was also accused of failing to pursue the murderers of his predecessor and of purging ʿUthmān’s supporters from office. Foremost among his opponents was Muʿāwiyah, the governor of Syria and a relative of ʿUthmān, who claimed the right to avenge ʿUthmān’s death. In his confrontation with Muʿāwiyah, ʿAlī was supported by the anṣār and the people of Iraq. Before he could act, however, he had to deal with the rebellion of two senior companions, Talḥah and Zubayr. Joined by ʿĀʾishah, daughter of Abū Bakr and third wife of Muhammad, the two had marched upon Basra and captured it. ʿAlī assembled an army in Kufa, which became his capital, and met the rebels in 656 at the Battle of the Camel. Although a peaceful settlement had nearly been reached before the fighting started, extremists on both sides forced the battle, in which ʿAlī’s forces were victorious. Talḥah and Zubayr were killed, and ʿĀʾishah was conducted safely back to Medina.

ʿAli then turned his attention north to Muʿāwiyah, engaging him in 657 at the Battle of Siffin, the most important contest of early Islamic history after the death of the Prophet. With his army on the verge of defeat, Muʿāwiyah, on the advice of one of his supporters, ʿAmr ibn al-ʿAṣ, ordered his soldiers to put pages of the Qurʾān on their lances and asked ʿAlī to allow the dispute to be resolved by reference to Qurʾānic rules. ʿAlī’s army, seeing the sacred text, put down its arms, and ʿAlī was forced to arbitrate. He chose an upright observer, Abū Mūsā al-Ashʿarī, and Muʿāwiyah chose ʿAmr ibn al-ʿAṣ. After ʿAlī lost the arbitration, Muʿāwiyah refused to submit to his authority; Muʿāwiyah then defeated ʿAlī’s forces in Egypt, where ʿAmr ibn al-ʿAṣ became governor.

Matters were made even worse by the fact that a group that considered arbitration to be a violation of the teachings of the Qurʾān rebelled against ʿAlī while also opposing Muʿāwiyah. ʿAlī’s attempts to reason with the rebels failed, and they left Kufa and Basra and assembled at Al-Narhawān. In 658 ʿAlī’s army dealt a crushing blow to the group that came to be known as the Khārijites (“Seceders”).

Although he continued to have staunch supporters, ʿAlī’s authority was weakened in many areas during the last two years of his caliphate. A number of prominent Muslims even met in Adrūh in 659 with the thought of deposing both ʿAlī and Muʿāwiyah and appointing as caliph ʿAbd Allāh, son of ʿUmar, but they did not reach a final decision. Meanwhile, some of the Khārijites decided to assassinate ʿAlī, Muʿāwiyah, and ʿAmr ibn al-ʿAṣ. Although the latter two escaped, ʿAlī did not: on the 19th of Ramadan in the year 661, he was struck in the back of the head with a poisoned sword while praying in the mosque of Kufa. He died two days later and was buried in Najaf. Along with Qom in Iran, Najaf became—and remains to this day—one of the most important seats of Shiʿi learning and also a major pilgrimage site.