Umar al-Aqta, Arab emir
ʿUmar ibn ʿAbdallāh ibn Marwān, ʿAmr ibn ʿUbaydallāh ibn Marwān, or simply Umar al-Aqta (Arabic: عمر الأقطع) surnamed al-Aqtaʾ, "the one-handed" (μονοχεράρης, monocherares, in Greek), and found as Amer or Ambros (Greek: Ἄμερ or Ἄμβρος) in Byzantine sources, was the semi-independent Arab emir of Malatya (Melitene) from the 830s until his death in the Battle of Lalakaon on 3 September 863. During this time, he was one of the greatest threats to the Byzantine Empire on its eastern frontier, and became a prominent figure in later Arabic and Turkish epic literature.