The Battle of Anzen was fought on 22 July 838 between the forces of the Byzantine Empire led by Theophilos and Abbasid Caliphate. The Abbasids has launched a huge expedition with two separate armies in retaliation for the Byzantine Emperor Theophilos’s successes the previous year. Theophilos with his army confronted the smaller Muslim army, under the Iranian vassal prince Afshin, at Dazimon.
As the young Theophilos ascended the Byzantine throne in 829, the Arab–Byzantine wars had continued on and off for almost two centuries. In 837 Theophilos led a vast army of 70,000 men towards Mesopotamia and captured Melitene and Arsamosata. The Emperor also took and destroyed Zapetra, which some sources claim as the birthplace of Caliph al-Mu'tasim.
Theophilos returned to Constantinople in triumph. Eager for revenge, Al-Mu'tasim assembled a vast army and launched a two-pronged invasion of Anatolia in 838. Theophilos decided to strike one division of the caliph's army before they could combine. On 22 July 838 at the Battle of Anzen in Dazimon, Theophilos personally led a Byzantine army of 25,000 to 40,000 men against the troops commanded by al-Afshin. Afshin withstood the Byzantine attack, counter-attacked, and won the battle.
Depicted here is copper Follis minted in large quantities in celebration of Theophilos' victories against the Arabs from ca. 835 on. On the obverse he is represented in triumphal attire, wearing the toupha, and on the reverse the traditional acclamation "Theophilos Augustus, you conquer".< br>
Image Source: Wikipedia.org