A caliphate is an Islamic state led by a supreme leader known as a caliph, a successor, to Muhammad and the other prophets of Islam.
A caliphate (from the Arabic: خلافة khilāfa, meaning succession) is an Islamic state led by a supreme religious and political leader known as a caliph, i.e. successor, to Muhammad and the other prophets of Islam. The succession of Muslim empires that have existed in the Muslim world are usually described as "caliphates". Conceptually, a caliphate represents a theocratic sovereign state of the entire Muslim faithful (the Ummah, i.e. a sovereign nation state) ruled by a single caliph under the Constitution of Medina and Islamic law (sharia).