Soran, Sorant, Sorehaut, Sorham, Sorhan, Sorhaute, Sourchault, Sourehault
Malory mentions this British city as:
a city that hight Sorhaute, the which city was within King Uriens' [land].
This would put it in Gore.
In the Vulgate Lancelot, it is a city belonging to Galehaut (Galeholt) and Urien in the Vulgate Merlin. In the latter it was the capital of Gorre, and it served as a base of operation for the northern kings in their battles against the Saxons. Lancelot names it as the chief city of Sorelois.
Sources
Lancelot of the Laik | Late 15th century
Vulgate Lancelot | 1215-1230
Vulgate Merlin | 1220-1235
Arthour and Merlin | Late 13th century
Le Morte Darthur | Sir Thomas Malory, 1469-1470