Sack of Amorium

The siege of Amorium by the Abbasid Caliphate in mid-August 838 was one of the major events in the long history of the Arab–Byzantine Wars. The Abbasid campaign was led personally by the Caliph al-Mu'tasim (r. 833–842), in retaliation to a virtually unopposed expedition launched by the Byzantine emperor Theophilos (r. 829–842) into the Caliphate's borderlands the previous year.