Diyar Mudar encompasses the region on both banks of the middle course of the river Euphrates, from the area of Samosata to the town of Anah, and includes the area of the Balikh River and the lower reaches of the river Khabur. Its main cities were Raqqa in the south and Edessa (al-Ruha in Arabic) in the north, and other major cities included Harran, and Saruj (now Suruç).