Jacob bar Shakkō (d. 638-9/1240-1), known also as Severus, was a Syrian Orthodox Christian monk and scholar. Born in the village of Barṭelli, east of Mosul, he entered the nearby monastery of Mār Mattay, and later became its abbot and bishop. The way in which his name is recorded in the sources suggests that Jacob was his episcopal name, while the more episcopal-sounding Severus was the name by which he was known before becoming bishop. Barhebraeus (d. 685/1286, Chronicon ecclesiasticum , Louvain 1872-7, 2:409-