A beautiful and delightful island off the southern coast of Britain.
Constantine, Arthur’s grandfather, laid low on the island and trained his army before entering Britain and destroying the barbarian invaders. Later, Totnes was used as a haven for Constantine’s sons – Ambrosius Aurelius and Uther – when they came from Brittany to take Britain from Vortigern.
During Arthur’s reign, Colgrim’s Saxons conquered the area in betrayal of a peace treaty they had made with Arthur.
Source
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138