Diyar Mudar (Arabic:دِيَارُ مُضَرَ,romanized: Diyār Muḍar,lit. 'abode of Mudar') is the medievalArabic name of the westernmost of the three provinces ofal-Jazira (Upper Mesopotamia), the other two beingDiyar Bakr andDiyar Rabi'a. According to the medieval geographeral-Baladhuri, all three provinces were named after the main Arab tribes that were settled there byMu'awiya I in the course of theearly Muslim conquests of the 7th century. The Diyar Mudar was settled by theMudar tribe.
Diyar Mudar encompasses the region on both banks of the middle course of the riverEuphrates, from the area ofSamosata to the town ofAnah, and includes the area of theBalikh River and the lower reaches of the riverKhabur. Its main cities wereRaqqa in the south andEdessa (al-Ruha in Arabic) in the north, and other major cities includedHarran, and Saruj (nowSuruç).
Geographically and politically, in early Islamic times the Diyar Mudar was usually part of al-Jazira. In the mid-10th century, the region came underHamdanid control, and underSayf al-Dawla it was detached from the Jazira and the Hamdanids ofMosul and subordinated to the northern Syria-basedEmirate of Aleppo. In the same period, the region came under attack by the resurgentByzantine Empire.
After the loss of control of the Hamdanids, the Diyar Mudar and its cities came under the sway of theBanu Numayr, withWaththab ibn Ja'bar al-Numayri becoming autonomous governor of Harran by 1002, while Edessa was conquered by theByzantine Empire underGeorge Maniakes in 1032. Thereafter the region became divided into a mostly Christian-ruled northern portion, subject toArmenian colonization, while the area from Harran to the Euphrates was dominated by Arab nomadic tribes.Seljuk raids began in the 1060s and 1070s but they could not take the region. After the battle of Manzikert,Philaretos Brachamios appointedThoros as governor of Edessa and the Diyar Mudar, but Thoros retreated after some time to Melitene (though he was reappointed again as governor by the Seljuks in 1094).[1]
By 1086 the SeljuksultanMalik-Shah I had unified the province under his control. The advent of theCrusades re-established the division between a Christian north (theCounty of Edessa) and a Muslim south, which lasted until the mid-12th century. TheAyyubids gained control of the region underSaladin, and kept it until theMongol invasion of the Levant in 1260.