Lohengrin (lō`ən-grĭn), in medieval German story, a knight of the Holy Grail Grail, Holy, a feature of medieval legend and literature. It appears variously as a chalice, a cup, or a dish and sometimes as a stone or a caldron into which a bleeding lance drips.
..... Click the link for more information. , son of Parzival. He is sent to rescue Princess Elsa of Brabant from an unwanted suitor. Led to Antwerp by a swan, Lohengrin saves Elsa and marries her. She is forbidden to ask his identity, but, overcome by curiosity, she asks. As a result, Lohengrin must return to the castle of the Grail. The swan reappears and is revealed to be Elsa's brother. In its fullest form the story is treated in a German epic poem composed c.1285–1290 and ascribed to Wolfram von Eschenbach Wolfram von Eschenbach (vôl`främ fən ĕsh`ənbäkh), c.1170–c.1220, German poet.
..... Click the link for more information. by its unknown author. Wagner based his libretto for the opera Lohengrin (1850) on this source. The swan's metamorphosis is also a theme in classical, Celtic, and other mythologies.

Lohengrin

The tower of Swans' Castle (Schwanenburg), Kleve, Ger., associated with the legend of Lohengrin

(credit: 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).

Lohengrin

defeats Telramund in trial by combat; spares him. [Ger. Opera: Wagner, Lohengrin, Westerman, 215]

See : Noblemindedness