"Walküre" is the second opera in Richard Wagner's Der Ring des Nibelungen cycle. Premiering in 1870, it tells the story of Brünnhilde, a Valkyrie, who defies her father, Wotan, the chief god, to protect a mortal hero, Siegmund. The opera explores themes of love, sacrifice, and fate. The music of "Walküre" is renowned for its emotional depth and powerful orchestration. One of its most famous scenes is the "Ride of the Valkyries," which depicts the Valkyries gathering fallen warriors. The opera is a cornerstone of the Western classical music repertoire and has influenced many composers and artists.