After the death of his father, prince Tristan is living in Cornwall at the court of his uncle, King Marke, who treats him like a son. When the Irish king sends his son Morold over to demand high tax payments, Tristan challenges him to combat. He manages to kill Morold but is very badly injured, and is placed in a boat to be healed by the magic powers of the sea, which takes him across to Ireland. There he is discovered by Isolde, Morold`s sister, who nurses him back to health together with her mother. Before his identity becomes known, Tristan travels back to Cornwall where the barons are urging King Marke to finally choose a wife for himself. When the king hears of Isolde`s beauty he sends Tristan across to bring her back to him as a bride. Isolde is appalled at the way her father welcomes Morold`s murderer, and at his desire to marry her off to a strange king.