Answer
His surname, Al-Jazari, is derived from his birthplace, Jazirat ibn Umar, a town located in present-day Turkey, which during his lifetime was part of the Artuqid dynasty, a branch of the Seljuk Turks. The name Jazirat ibn Umar means "the Island of Umar's Son", referring to the town's location on an island in the Tigris River.