science Al-Mu'tasim was the eighth Abbasid caliph, ruling from 833 until his death in 842. The younger son of Caliph Harun al-Rashid. He is also known for founding the city of Samarra. Al-Mutawakkil was the tenth Abbasid caliph who reigned from 847 until 861. He was the son of al-Mu'tasim. He is considered an influential Abbasid caliph. Al-Mu'tadid was the caliph of the Abbasid Caliphate from 892 until his death in 902. Ar-Radi was the twentieth Abbasid caliph, reigning from 934 to his death. He died on 23 December 940 at the age of 31. He is considered the last caliph of early Abbasid period. Al-Qadir, famous caliph of later Abbasid period, 991–1031. Al-Muqtafi, famous caliph of later Abbasid period, who reigned 1136–1160. Al-Nasir was the Abbasid caliph in Baghdad from 1180 until his death in 1225. According to the historian, Angelika Hartmann, Al-Nasir was the last effective later Abbasid caliph. Al-Musta'sim was the 37th and last Abbasid caliph to rule from Baghdad. He ruled from 1242 until his death in 1258. "Ottoman Caliphate" Selim I, the 9th Sultan, the 1st caliph and maiden title holder of "Custodian of the Two Holy Mosques" of the Ottoman Empire. Under his reign, the Empire grew by seventy per cent. Suleiman the Magnificent, the 2nd Ottoman caliph, during whose reign the Ottoman Empire reached its zenith Ahmed I, the 8th Ottoman caliph, who is well known for his construction of the Blue Mosque, one of the most famous mosques and tourist attraction in Turkey. Abdul Hamid II, the 25th and the last Ottoman caliph to rule with independent, absolute power Mehmed V, the 26th Ottoman caliph, who made the Ottoman Empire enter into World War I in 1914, which would ultimately lead to the Empire's end. Abdulmejid II, the 28th and the last caliph of the Ottoman dynasty. Nominally the 37th Head of the Ottoman dynasty. In 1924, Grand National Assembly of Turkey abolished the Ottoman Caliphate and sent Mejid in exile. See also References Citations Sources Further reading The theory of government in Islam, by The Internet Islamic University The History of Al-Khilafah Ar-Rashidah (The Rightly Guided Caliphates) School Textbook, By Dr. 'Abdullah al-Ahsan, `Abdullah Ahsan The Crisis of the Early Caliphate By Richard Stephen Humphreys, Stephen (EDT) Humphreys from The History of al-Tabari The Reunification of the Abbasid Caliphate By Clifford Edmund (TRN) Bosworth, from The History of al-Tabari Return of