List of caliphs

A caliph is the supreme religious and political leader of an Islamic state known as the caliphate.^[1][2] Caliphs led the Muslim Ummah as political successors to the Islamic prophet Muhammad,^[3] and widely-recognised caliphates have existed in various forms for most of Islamic history.^[4]

The first caliphate, the Rashidun Caliphate, was ruled by the four Rashidun caliphs (Arabic: الخلفاء الراشدون, lit. 'Rightly Guided Caliphs'), Abu Bakr, Umar, Uthman and Ali, who are considered by Sunni Muslims to have been the most virtuous and pure caliphs. They were chosen by popular acclamation or by a small committee, in contrast with the following caliphates, which were mostly hereditary.^[5] On the other hand, Shiites only recognise Ali and consider the first three caliphs to be usurpers.

The Rashidun caliphate ended with the First Fitna, which transferred authority to the Umayyad dynasty that presided over the Umayyad Caliphate, the largest caliphate and the last one to actively rule the entire Muslim world.^[6]

The Abbasid Revolution overthrew the Ummayads and instituted the Abbasid dynasty which ruled over the Abbasid Caliphate.^[7] The Abbassid Caliphate was initially strong and united, but gradually fractured into several states whose rulers only paid lip service to the caliph in Baghdad. There were also rivals to the Abbasids who claimed the caliphates for themselves, such as the Isma'ili Shia Fatimids, the Sunni Ummayyads in Córdoba and the Almohads, who followed their own doctrine. When Baghdad fell to the Mongols, the Abbassid family relocated to Cairo, where they continued to claim caliphal authority but had no political power, and actual authority was in the hands of the Mamluk Sultanate.

After the Ottoman conquest of Egypt, the Abbasid caliph Al-Mutawakkil III was taken to Constantinople, where he surrendered the caliphate to the Ottoman Sultan Selim I. The caliphate then remained in the House of Osman until after the First World War. The Ottoman Sultanate was abolished in 1922 by the Grand National Assembly of Turkey. The head of the House of Osman, Abdulmejid II, retained the title of caliph for two more years, after which the caliphate was abolished in 1924.