Arestuel, Arestueil
A wooded region in Scotland, known for its fine hunting grounds.
During Arthur’s reign, it was twice invaded by Saxons. On the fist occasion, King Lot of Lothian called a meeting of all the nobles there, proposing that the princes in rebellion against Arthur ally with him temporarily to face the Saxon threat.
On the second invasion, Arthur met the Saxons there (at nearby Saxon Rock) and, with the help of Lancelot, drove them away.
Sources
Lancelot do Lac | 1215-1220
Vulgate Lancelot | 1215-1230
Vulgate Merlin | 1220-1235