Caliph
The Caliph is the head of state in a Caliphate, and the title for the leader of the Islamic Ummah, an Islamic community ruled by the Shari'a. The early leaders of the Muslim nation following Muhammad's (570–632) death were called "Khalifat Rasul Allah", meaning the political successors to the messenger of God (referring to Muhammad).
Caliphs were often also referred to as Amīr al-Mu'minīn "Commander of the Faithful", Imam al- Ummah or more colloquially, leader of the Muslims. After the first four caliphs ( Abu Bakr, Umar ibn al-Khattab, Uthman ibn Affan, and Ali ibn Abi Talib), the title was claimed by the Umayyads, the Abbasids, and the Ottomans, and at times, by competing dynasties in Spain, Northern Africa, and Egypt. Most historical Muslim governors were called sultans or amirs, and gave allegiance to a caliph, but at times had very little real authority. The title has been defunct since the Republic of Turkey abolished the Ottoman Caliphate in 1924, although some individuals and groups have called for its restoration.
Prominent men of a kinship group, or tribe, gather after a leader's death and elect a leader from amongst themselves. There was no specified procedure for this shura, or consultation. Candidates were usually from the same lineage as the deceased leader, but they were not necessarily. Capable men who would lead well were preferred over an ineffectual heir.
The question of who should succeed Muhammad was not the only issue that faced the early Muslims; they also had to clarify the extent of the leader's powers. Muhammad, during his lifetime, was not only the Muslim political leader, but the Islamic prophet. All law and spiritual practice proceeded from Muhammad. Some claimed that his successor would be a prophet; succession referred to political authority. The uncertainty centered on the extent of that authority. Muhammad's revelation claim to be directly from God, were soon codified and written down as the Qur'an, which was accepted as a supreme authority, limiting what a caliph could legitimately command.
However, there is some evidence that some early caliphs did believe that they had authority to rule in matters not specified in the Qur'an.
