Son of Harun al-Rashid and the seventh Abbasid caliph, renowned for his patronage of learning and the translation movement (Bayt al-Hikma). During his campaign against Byzantium he died on 18 Rajab 218 (9 August 833) at a camp near the Bedendûn (Pozantı) water. Per the tradition of keeping caliphs' graves hidden, his body is said to have been brought to Tarsus and buried in the garden of the governor's house, which over time was demolished and enclosed within the expanded Tarsus Grand Mosque; his maqam is today in the mosque's eastern section. Though a political ruler, he is recorded here as a scholar/historical figure for his central role in the history of Islamic learning. (Sources: TDV İslâm Ansiklopedisi 'Me'mûn'; TDV İslâm Ansiklopedisi 'Tarsus'.)