THEOPHILUS, East Roman emperor (829-842), the second of the Phrygian dynasty, a pronounced iconoclast. In 832 he issued an edict strictly forbidding the worship of images. His whole reign was occuped in war against the caliphs of Baghdad. This war was caused by Theophilus, who afforded an asylum to a number of Persian refugees. The Roman arms were at first successful; in 837 Samosata and Sibatra (Zapetra, Sozopetra), the birthplace of al-Mu'tasim, were taken and destroyed. Eager for revenge, al-Mu'tasim assembled a vast army, one division of which defeated Theophilus, who commanded in person, at Sasymon, while the other advanced against Amorium, the cradle of the Phrygian dynasty. After a brave resistance the city fell into al-Mu'tasim's hands through treachery. Thirty thousand of the inhabitants were slain, and the city razed to the ground.
Theophilus never recovered from the blow, and he died at the beginning of 842