Rashidun Caliphate

Muhammad died in 632 without a son and, on the Sunni account, without naming a successor. While his household prepared the burial, an assembly of Medinan and Meccan leaders met at the portico of the Banu Saida and acclaimed Abu Bakr as khalifa, successor or deputy, a title that carried no prophetic authority. Umar followed in 634, Uthman in 644 and Ali, the Prophet's cousin and son in law, in 656. Three of the four were murdered.

The disagreement about whether this was the right sequence is the origin of the Sunni and Shia division. Shia tradition holds that Muhammad had designated Ali, most explicitly at Ghadir Khumm, and that the community set the designation aside. Wilferd Madelung's study argues, from the Sunni sources themselves, that the case for Ali's claim was considerably stronger than the later Sunni consensus allowed, and that the early caliphate is better read as a contested political settlement than as a smooth succession.

Uthman's reign produced the single most consequential act of the period, the establishment of an authoritative written text of the Quran and the withdrawal of competing copies, and also the grievances, over governorships given to his kinsmen, that led to his murder in 656. The first fitna followed, Ali against the Prophet's widow Aisha at the Battle of the Camel and then against Muawiya at Siffin, where arbitration split off the Kharijites, one of whom killed Ali in 661.

The speed of the conquests is the hardest fact of the period to absorb. Within twenty years of the Prophet's death, armies from Arabia had taken Syria after the Yarmuk in 636, Iraq after Qadisiyya, Jerusalem in 638, Egypt by 642 and the Persian heartland by the early 650s, against two empires that had just exhausted each other in a generation of war. Conquest did not mean conversion. The armies were settled in new garrison cities, Kufa, Basra and Fustat, deliberately apart from the populations they governed, and the great majority of those populations remained Christian, Jewish or Zoroastrian for centuries.

The legal shape of that arrangement is the dhimma, the protected status of scriptural communities, who kept their own law, courts and worship in exchange for a tax and for accepting subordination. Milka Levy-Rubin's work shows that the terms were originally negotiated locally at surrender and were far less uniform than the later law books suggest, and that the restrictive conditions attached to the status hardened considerably after the first century.

The caliph himself was not a prophet and made no claim to revelation. He led prayer, commanded the armies, appointed governors and judges, and distributed the conquest revenue; the definition of doctrine was not among his powers, and the failure of a later caliph to seize it would settle the point permanently.