The caliphate began as an urgent, unplanned decision. Muhammad died in 632 without naming a successor in any way all his followers accepted as final, and a meeting at Saqifa in Medina resulted in the community's leading men choosing Abu Bakr as the first caliph, while a minority held that Ali, the Prophet's cousin and son in law, had the stronger claim, a disagreement that hardened over the following decades into the enduring Sunni and Shia division. The office passed from the first four caliphs, later called Rashidun, to the Umayyad dynasty ruling from Damascus after 661, then to the Abbasids ruling from Baghdad after 750, each transition marked by conquest rather than agreed procedure. Unity under one caliph did not last: by the tenth century a Fatimid caliph ruled from Cairo and an Umayyad caliph ruled from Cordoba at the same time as the Abbasid caliph in Baghdad, three men simultaneously claiming the same office. The institution persisted in weakened and later largely symbolic forms for centuries afterward until the Turkish Republic under Mustafa Kemal Ataturk abolished it outright in 1924, ending an office that had existed in some form for nearly thirteen hundred years.
The Ottoman sultans had claimed the title for themselves from around the sixteenth century onward, giving the office a final, extended life inside their own empire even as its practical authority over the wider Muslim world had long since become nominal, so that its formal abolition in 1924 closed a claim already centuries removed from any single ruler's real command of the whole ummah.