Diyar Mudar

According to the medieval geographer 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.

Geographically and politically, in early Islamic times the Diyar Mudar was usually part of al-Jazira.

After the loss of control of the Hamdanids, the Diyar Mudar and its cities came under the sway of the Banu Numayr, with Waththab ibn Ja'bar al-Numayri becoming autonomous governor of Harran by 1002, while Edessa was conquered by the Byzantine Empire under George Maniakes in 1032.

Thereafter the region became divided into a mostly Christian-ruled northern portion, subject to Armenian colonization, while the area from Harran to the Euphrates was dominated by Arab nomadic tribes.

The advent of the Crusades re-established the division between a Christian north (the County of Edessa) and a Muslim south, which lasted until the mid-12th century.