Old French form of the Pictish name Drustan, a diminutive of Drust. The spelling was altered by association with Latin tristis "sad". Tristan is a character in medieval French tales, probably inspired by older Celtic legends, and ultimately merged into Arthurian legend. According to the story Tristan was sent to Ireland in order to fetch Isolde, who was to be the bride of King Mark of Cornwall. On the way back, Tristan and Isolde accidentally drink a potion which makes them fall in love. Their tragic story was very popular in the Middle Ages, and the name has occasionally been used since that time.