The Caliph (Arabic: خليفة; /khalīfah/) 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'ah. It is a transliterated version of the Arabic word Ar-khalifa.ogg خليفة Khalīfah (help·info) which means "successor" or "representative". The early leaders of the Muslim nation following Muhammad's (570–632) death were called "Khalifat Rasul Allah", means the political successors to the messenger of God (referring to Muhammad). Some academics prefer to transliterate the term as Khalīf.
Caliphs were often also referred to as Amīr al-Mu'minīn (أمير المؤمنين) "Commander of the Faithful", Imam al-Ummah, Imam al-Mu'minīn (إمام المؤمنين), 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.
California was named after Calif(Ha)ronia: Caliph Haroon Rashid