The tower of Swans' Castle (Schwanenburg), Kleve, Ger., associated with the legend of Lohengrin—Stief Pictures, Frankfurt
Hero-knight of medieval Germanic legends. He was called the knight of the swan because he arrived in a boat drawn by a swan to help a noble lady in distress. He married her but forbade her to ask his origin; when she forgot this promise, he left her, never to return. The first version of his legend appeared c. 1210 in Wolfram von Eschenbach's Parzival, in which the swan knight was the son and heir of Parzival (Perceval). The anonymous 15th-century epic Lorengel provided the basis for Richard Wagner's opera Lohengrin (1850).