Tristan and Isolde, Tristan also called Tristram or Tristrem, Isolde also called Iseult, Isolt, or Yseult, principal characters of a famous medieval love-romance, based on a Celtic legend (itself based on an actual Pictish king). Though the archetypal poem from which all extant forms of the legend are derived has not been preserved, a comparison of the early versions yields an idea of its content. The central plot of the archetype must have been roughly as follows: The young Tristan ventures to Ireland to ask the hand of the princess Isolde for his uncle, King Mark of Cornwall, and, having