Mamun, al-(Abu al-Abbas Abd Allah al-Mamun) (mämo͞on`), 786–833, 7th AbbasidAbbasid
, Arab family descended from Abbas, the uncle of Muhammad. The Abbasids held the caliphate from 749 to 1258, but they were recognized neither in Spain nor (after 787) W of Egypt.
..... Click the link for more information. caliph (813–33); son of Harun ar-RashidHarun ar-Rashid
[Arab.,=Aaron the Upright], c.764–809, 5th and most famous Abbasid caliph (786–809). He succeeded his brother Musa al-Hadi, fourth caliph, a year after the death of his father, Mahdi, the third caliph.
..... Click the link for more information. . He succeeded his brother al-Amin after a bitter civil war, but was unable to enter Baghdad until 819. He was himself one of the Mutazilites, holding that the Qur'an was created in time, i.e., that it was not an uncreated eternal existent. He persecuted the orthodox bitterly. Al-Mamun's reign was one of great cultural achievement, and he was especially interested in the work of scientists, particularly of those who knew Greek. He established (830) in Baghdad the House of Wisdom, an institution that translated Greek works into Arabic.