Although the oldest stories concerning Tristan are lost, some of the derivatives still exist. Tristan made his first recorded appearance in the 12th century in British mythology circulating in the north of France and the Kingdom of Brittany, which had close ancestral and cultural links with Wales, Cornwall and Devon by way of the ancient British kingdom of Dumnonia, as made clear in the story itself, and the closely related Cornish and Breton languages, both of which are P-Celtic like Welsh. The pair then undergo numerous trials that test their secret affair, before the tragic end. However, he and Iseult accidentally consume a love potion while en route and fall helplessly in love. In the story of Tristan and Iseult, Tristan is the nephew of King Mark of Cornwall, sent to fetch Iseult back from Ireland to wed the king. Richard Wagner's influential 19th-century opera Tristan und Isolde portrays Tristan as a doomed romantic figure. He has been depicted in numerous historical and modern works of literature, music, and cinema. The historical roots of Tristan are unclear his association with Cornwall may originate from the Tristan Stone, a 6th-century granite pillar in Cornwall inscribed with the name Drustanus (a variant of Tristan). He is featured in Arthurian legends, including the seminal text Le Morte d'Arthur, as a skilled knight and a friend of Lancelot. The character's first recorded appearance is in retellings of British mythology from the 12th century by Thomas of Britain and Gottfried von Strassburg, and later in the Prose Tristan. Tristan and Iseult accidentally drink a love potion during the journey and fall in love, beginning an adulterous relationship that eventually leads to Tristan's banishment and death. In the legend, he is tasked with escorting the Irish princess Iseult to wed Tristan's uncle, King Mark of Cornwall. Tristan ( Latin/ Brythonic: Drustanus Welsh: Trystan), also known as Tristram or Tristain and similar names, is the hero of the legend of Tristan and Iseult. Tristán e Iseo (La vida) by Rogelio de Egusquiza (1912)