‘Umar ibn ‘Abdallah ibn Marwan (his first name also is variously rendered as ‘Amr or ‘Omar), surnamed al-Aqta’, "the one-handed", and found as Amer or Ambros (Greek: Ἄμερ or Ἄμβρος) in Byzantine sources, was the Arab emir of Malatya (Melitene) from the 830s until his death in battle in 863. During this time, he was one of the greatest enemies of the Byzantine Empire on its eastern frontier.[1][2]
He first appears in the sources during the 830s, when he participated in the Abbasid campaigns against Byzantium, among them the great Arab victory over the Byzantine emperor Theophilos (r. 829–842) at Dazimon in July 838.[2] In the 840s he provided shelter to the surviving members of the Paulicians, who were fleeing persecution in Byzantium, and allocated them the area around Tephrike. The Paulician leader Karbeas turned this into a separate Paulician principality, allied with 'Umar and launching frequent expeditions against Byzantium, either in conjunction with 'Umar or independently.[2][3][4] In 844, 'Umar's forces inflicted a heavy defeat upon an army led by the Byzantine chief minister, Theoktistos, at Mauropotamos. After this victory, his army raided as far as the Bosporus, and several prominent Byzantines reportedly went over to him. In the late 840s he was also engaged in warfare against a neighbouring Armenian lord named Skleros, whom he finally vanquished after a protracted and bloody conflict.[2][5]
In the 850s, he is recorded as having defeated an expedition led by the Byzantine emperor Michael III (r. 842–867) against Samosata, and to have carried out a number of successful raids into Byzantium. One of them swept through the themes of Thrakesion and Opsikion and came up to the great Byzantine army base of Malagina in Bithynia.[2] He was unable however to stop a retaliatory expedition launched in 856 by Petronas the Patrician against Melitene and Tephrike, which raided all the way to Amida, taking many prisoners before returning home.[6] In 860, along with Karbeas he launched a major raid into Anatolia which reached the Black Sea port of Sinope, returning with over 12,000 heads of captured livestock.[6][7] Three years later, he was part of a major Abbasid force that invaded Anatolia through the Cilician Gates. After splitting off from the main force and repulsing a Byzantine army under Michael III at Mardj al-Usquf ("Bishop's Meadow") in Cappadocia, 'Umar with his men headed north to sack the port city of Amisos. On his return however, he was encircled by the Byzantines and killed at the Battle of Lalakaon on 3 September 863. Only a splinter of his army escaped under his son, but was then defeated and captured by the commander of the Charsianon district.[3][8][9][10] His death marked the end of Malatya as a military threat to Byzantium, although the emirate would survive as an independent power until its conquest by the Byzantine general John Kourkouas in 934.[11]