Umar al-Aqta

'the one-handed'; μονοχεράρης, monocherares, in Greek), and found as Amer or Ambros (Ἄμερ or Ἄμβρος) in Byzantine sources,[1] was the semi-independent Arab emir of Malatya (Melitene) from the 830s until his death in the Battle of Lalakaon on 3 September 863.

The campaign was waged in retaliation for a large-scale raid in the previous year by the Byzantine emperor Theophilos (r. 829–842) against the Arab border emirates, including Malatya, whose territory was laid waste and depopulated.

After splitting off from the main force and repulsing a Byzantine army under Emperor Michael III at Mardj al-Usquf ("Bishop's Meadow") in Cappadocia, ʿUmar with his men headed north to sack the port city of Amisos.

[1][3][11][12] According to al-Tabari, when the news of ʿUmar's death, along with that of another celebrated leader, Ali ibn Yahya al-Armani, arrived in Iraq, they provoked riots among the populace of Baghdad, Samarra, and other cities, angry at the Abbasid government's perceived incompetence.

The German scholar Hans-Georg Beck finds this identification unlikely, but points out the reference to a "short-armed" Arab leader in the same tale, which may reflect a folk tradition based on ʿUmar.

[19] Finally, the 10th-century scholar al-Mas'udi reports (The Meadows of Gold, VIII, 74–75) that ʿUmar was among the "illustrious Muslims" whose portraits were displayed in Byzantine churches in recognition of their valour.