Tristan, a young warrior from Cornwall, is sent by his uncle, King Mark, to Ireland to bring back Isolde to marry Mark and unite their kingdoms. During the journey back to Cornwall, Tristan and Isolde fall deeply in love despite the fact that they are enemies due to the ongoing feud between their countries.
Upon their arrival in Cornwall, Isolde marries Mark, but she cannot deny her feelings for Tristan, and they begin a secret affair. However, their happiness is cut short when they are discovered by Mark, who banishes Tristan from the kingdom.
Tristan and Isolde continue to secretly meet, but their love is threatened by political tensions and the knowledge that their relationship cannot continue. In a final desperate attempt to be together, they plan to leave Cornwall and start a new life in another country. However, their plan is betrayed, and in the resulting battle, both Tristan and Isolde are fatally wounded.
The film is a tragic tale of doomed love, political intrigue, and the consequences of choosing love over duty.