Sir Sadok, flying from Mark’s ambush at Tintagil, passed Lyonesse Castle and continued to Arbray, where he found Sir Dinas, the Seneschal of Cornwall. They gathered the people and stocked the towns and castles of Cornwall and made a pact to defect from the court of King Mark.
Arbray Castle, therefore, appears to have been within the land of Lyonesse or Cornwall.
Prose Tristan | 1230-1240
Le Morte Darthur | Sir Thomas Malory, 1469-1470