In 860, along with Karbeas, ʿUmar launched a major raid into Anatolia which reached the Black Sea port of Sinope, returning with over 12,000 head of captured livestock. 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 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. 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. 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.