A knight whose sister was raped by King Mark of Cornwall. With his brother Helyas, Assar fled Mark's kingdom for the Island of Two Brothers.

The brothers later broke when Helyas abducted Assar's wife. During the war, Assar found Tristan (Tristram) stranded on the Rock of Hermits and rescued him. In gratitude, Tristan agreed to help Assar against Helyas. Tristan killed Helyas in single combat.