The Nibelungenlied (The Song of the Nibelungs) is the most famous heroic poem in Middle High German. It tells the story of the dragon-slayer Siegfried from his childhood and his marriage to Kriemhild to his murder by the evil Hagen and Kriemhild's subsequent revenge, culminating in the annihilation of the Burgundians or Nibelungs at the court of the Huns. Originally based upon an older oral tradition, the poem was written down about or shortly after the year 1200, probably at the court of Wolfger von Erla, Bishop of Passau from 1191 to 1204. Today it is known only in the versions that have come down to the present in 37 manuscripts and fragments dating from the 13th to the 16th centuries. In the 19th century, the Nibelungenlied had an enormous influence as a German national epic poem, as reflected in numerous works of visual art and in Richard Wagner's musical dramas. Codex A, which is preserved in the Bavarian State Library, was listed, together with two other primary manuscripts used to establish the text (Codices B and C), on the UNESCO Memory of the World register in 2009.