At that moment the blast of a trumpet was heard, followed by the voice of the herald as, for the last time, he challenged any knight to take up arms on behalf of Elsa of Brabant.  Lohengrin boldly accepted the challenge, and Telramund, when the news reached him of the unexpected opposition, on the very day he had appointed for his wedding, was surprised and enraged beyond measure, yet he dared not refuse to do battle with the stranger knight, because of the Emperor’s decree.  So it was arranged that the combat should take place immediately.  News of it reached the people of Cleves, and a great concourse gathered to witness the spectacle, all of them secretly in sympathy with the persecuted maiden, though these feelings were carefully concealed from the ruthless Telramund.

Fierce indeed was the combat, for Lohengrin, though less powerfully built than his gigantic opponent, was nevertheless tall and strong, and well versed in the arts of war.  At length he laid his enemy in the dust with a well-aimed sword-stroke, and the crowd broke into cheers.  The combat was over, and Elsa was free!

Heeding not the acclamations of the people, Lohengrin strode toward Elsa and again knelt at her feet.  The blushing maiden bade him name his reward, whereupon the knight begged her hand in marriage, confessing, however, that he might only remain with her so long as she did not question him with regard to his identity.  It seemed a small condition to Elsa, who willingly promised to restrain any curiosity she might feel concerning his name and place of abode.  The cheers of the populace were redoubled when they learned that Elsa was to bestow her hand on the Swan Knight.

In a few weeks the couple were married, and henceforth for a good many years they lived together very happily.  Three sons were born to them, who grew in time to be handsome and chivalrous lads, of noble bearing and knightly disposition.  Then it was that Elsa, who had hitherto faithfully kept her promise to her husband, began to fancy that she and her sons had a grievance in that the latter were not permitted to bear their father’s name.

For a time she brooded in silence over her grievance, but at length it was fanned into open rebellion by a breath of outside suspicion.  Some of the people looked askance at the knight whose name no one knew.  So Elsa openly reproached her husband with his secrecy, and begged that for the benefit of their sons he would reveal his name and station.  Even the children of humble parents, the children of the peasants, of their own retainers, had a right to their father’s name, and why not her sons also?

Lohengrin paled at her foolish words, for to him they were the sign that he must leave his wife and family and betake himself once more to the temple of the Holy Grail.

“Oh, Elsa,” he said sorrowfully, “thou knowest not what thou hast done.  Thy promise is broken, and to-day I must leave thee for ever.”  And with that he blew a blast on his silver horn.