Tristan and Iseult, WWV 90

Tristan und Isolde (Tristan and Isolde, or Tristan and Isolda, or Tristran and Ysolt) is an opera, or music drama, in three acts by Richard Wagner to a German libretto by the composer, based largely on the romance by Gottfried von Strassburg. It was composed between 1857 and 1859 and premiered at the Königliches Hof- und Nationaltheater in Munich on 10 June 1865 with Hans von Bülow conducting. Wagner referred to the work not as an opera, but called it "eine Handlung" (literally a drama, a plot or an action), which was the equivalent of the term used by the Spanish playwright Calderón for his dramas.