Al-Mu'tasim

Al-Mu'tasim (794-842) was the eighth Abbasid caliph, ruling from 833 until his death in 842, and a son of the earlier caliph Harun al-Rashid. He is best known for founding a new capital at Samarra, north of Baghdad, largely to house a growing corps of Turkic slave-soldiers, known as ghilman, whom he recruited in large numbers as a military force personally loyal to him rather than to the older Arab and Persian elites of the caliphate. This reliance on Turkic military slaves reshaped Abbasid politics for generations afterward, giving the military increasing influence over the caliphate's internal affairs. His reign also saw continued warfare against the Byzantine Empire, including a major campaign that captured the Byzantine city of Amorium in 838.