Roche as Saisnes
A Saxon outpost in Arestel, Scotland.
It was first occupied by Hengist during the reign of Vortigern. In one tale, it is the location where Uther Pendragon killed Hengist.
It served as a base of operations for the various Saxon invasions at the beginning and middle of Arthur’s reign. Its lady was Gamille (Camille), the sister of the Saxon King Hargadabran (Hargodabrans). Gamille used her charms to lure Arthur into her prison when Arthur traveled to the Rock to besiege the invading Saxons. Lancelot led an attack on the Rock, captured the castle, and freed Arthur.
Sources
Lancelot do Lac | 1215-1220
Vulgate Lancelot | 1215-1230
Vulgate Merlin | 1220-1235