838 CE

Babak Khorramdin, an Iranian military leader, is brutally executed by order of al-Mu'tasim. Battle of Anzen: Caliph al-Mu'tasim launches a major punitive expedition against the Byzantine Empire, targeting the two major Byzantine fortress cities of central Anatolia (Ancyra and Amorium). He mobilises a vast army (80,000 men) at Tarsus, which is divided into two main forces. The northern force, under commander al-Afshin, invades the Armeniac Theme from the region of Melitene, joining up with the forces of the city's emir, Umar al-Aqta. The southern, main force, under al-Mu'tasim, passes the Cilician Gates into Cappadocia. Emperor Theophilos attacks the Abbasids, inflicting 3,000 casualties, but is heavily defeated by a counter-attack of 10,000 Turkish mounted archers. Theophilos and his guard are encircled, and barely manage to break through and escape. Siege of Amorium: The Abbasids besiege the Byzantine fortress city of Amorium, which is protected by 44 towers, according to the contemporary geographer Ibn Khordadbeh. Both besiegers and besieged have many siege engines, and for several days both sides exchange missile fire. However, a Muslim prisoner defects to al-Mu'tasim, and informs him about a place in the wall which has been badly damaged by heavy rainfall. The Abbasids concentrate their hits on this section, and after two days manage to breach the city wall. After two weeks of repeated attacks, the Byzantine defenders surrender. The city is sacked and plundered, 70,000 inhabitants are slaughtered, and the survivors are sold as slaves.

In the 830s, the 9th century.