Tristan and Iseult

Tristan and Isolde by Herbert Draper (1901)

Tristan and Iseult, also known as Tristan and Isolde and other names, is a medieval legend told in numerous variations since the 12th century. Of disputed source, usually assumed to be primarily Celtic, the tale is a tragedy about the illicit love between the Cornish knight Tristan and the Irish princess Iseult in the days of King Arthur. During Tristan's mission to escort Iseult from Ireland to marry his uncle, King Mark of Cornwall, Tristan and Iseult ingest a love potion, instigating a forbidden love affair between them. Depending on the version, Tristan may marry another woman, Iseult of the White Hands, but never stops loving the Irish princess. The tale typically ends in their deaths from love and sorrow.