808 Edrisite dynasty founded at Fez.
809 Death of Harun on the way to quell disturbances in Khorasan. His reign is a flourishing period of art and science. His son, Emin, succeeds. His reign is mostly taken up with the rebellion of his brother, Mamun, who gradually wins all the provinces, except Baghdad, to his side.
813 Capture and assassination of Emin. Mamun proclaimed at Baghdad. The civil war continues.
817 Mamun appoints Musa b. Ali heir to the throne, whereupon the people of Baghdad declare Mamun deposed and elect his uncle, Ibrahim, caliph. Sudden death of Musa.
820 Appointment of Tahir as governor of Khorasan, where his descendants rule until 872—sometimes called Tahirite dynasty.
829 Euphemius invites the Mohammedans from Africa into Sicily. They take Palermo.
831 The Mohammedans begin a long invasion of Asia Minor.
832 Capture of Heraclea.
833 Death of Mamun. His reign is the Augustan age of Arabian literature. Works on science and philosophy translated from the Greek. Mamun orders the measurement of a degree of the earth’s circumference. The designated heir, his brother Mutasim, succeeds. A party in favour of Mamun’s son, Abbas, is put down. Mutasim employs Turks in his body-guard, and their excesses cause Baghdad to revolt. The caliph removes the capital to Samarra.
836 The emperor Theophilus destroys Zapetra in his savage war on the Moslems.