The lover of Tristan in medieval legend. She was the bride of Tristan's uncle Mark, the king of Cornwall, but on the way to Cornwall, both she and Tristan accidentally drink a love-potion that was meant for Mark and Iseult and their doomed love is born. Mark sometimes pursues them and at other times backs away but ultimately Tristan is banished to Brittany where he marries another Iseult, Iseult aux Blanches Mains. However, his love for the first Iseult never dies and out of loyalty to the Irish princess he is deterred from consummating his new relationship.