Der Ring des Nibelungen (The Ring of the Nibelung) is a cycle of four epic operas (or "dramas" to use the composer's preferred term) by the German composer Richard Wagner (1813–83). The works are based loosely on characters from the Norse sagas and the Nibelungenlied. The four dramas, which the composer described as a trilogy with a Vorabend ("preliminary evening"), are often referred to as the Ring Cycle, Wagner's Ring, or simply the Ring. Wagner wrote the libretto and music over the course of about twenty-six years, from 1848 to 1874. The four operas that constitute the Ring cycle are, in sequence: Das Rheingold (The Rhine Gold) Die Walküre (The Valkyrie) Siegfried Götterdämmerung (Twilight of the Gods) Although individual operas of the sequence are sometimes performed separately, Wagner intended them to be performed in series.