impossible to maintain peace in the East. Theophilos had given asylum to a number of refugees from the east in 834, including Nasr, a Persian. He baptized one of the refugees, Theophobos, who married the Emperor's aunt Irene and became one of his generals. As relations with the Abbasids deteriorated, Theophilos prepared for a new war. 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 (Zibatra, Sozopetra), 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 21 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. The Byzantine survivors fell back in disorder and did not interfere in the caliph's continuing campaign. Al-Mu'tasim took Ancyra, and al-Afshin joined him there. The full Abbasid army advanced against Amorium, the cradle of the dynasty. Initially there was determined resistance. Then a Muslim captive escaped and informed the caliph where there was a section of the wall that had only a front facade. Al-Mu'tasim concentrated his bombardment on this section, and the wall was breached. Having heroically held for fifty-five days, the city fell to al-Mu'tasim on 12 or 15 August 838. In 838, in order to impress the Caliph of Baghdad, Theophilus had John the Grammarian distribute 36,000 nomismata to the citizens of Baghdad. In 839 or 840, he initiated diplomatic contact with the Umayyad Emirate of Córdoba. The name of his ambassador is somewhat garbled in the Arabic accounts of Ibn Hayyan, but it seems to have been the admiral Karteros. He was accompanied on his return by the Córdoban poet al-Ghazal, who signed a pact of friendship with Theophilos directed against the Abbasids. Around 841, the Republic of Venice sent a fleet of 60 galleys (each carrying 200 men) to assist the Byzantines in driving the Arabs from Crotone, but it failed. During this campaign Al-Mu'tasim discovered that some of his top generals were plotting against him. Many of these leading commanders were arrested and some executed before he