Diyār Mudar ("abode of Mudar") is the medieval Arabic name of the westernmost of the three provinces of al-Jazira (Upper Mesopotamia), the other two being Diyar Bakr and Diyar Rabi'a. According to al-Baladhuri, all three provinces were named after the main Arab tribes that were settled there by Mu'awiya I in the course of the early Muslim conquests of the 7th century. The Diyar Mudar was settled by the Mudar tribe.