Successors to the prophet: Islam's caliphates

CAIRO (AP) — By declaring the establishment of an Islamic caliphate, the extremist group that controls large swaths of Syria and Iraq is claiming to be the successor of the political and religious community established by the Prophet Muhammad.

The caliphate is a powerful ideal — the concept of a nation of Muslims worldwide ruled by Shariah law under a caliph who holds both spiritual and secular authority. There have been multiple caliphates over Islam’s 1,400-year history, with the greatest Muslim empires ruling from Morocco to Central Asia.