Although this is the only motive that occurs in the Prelude, the ear never wearies of it. Its effectiveness is due to the wonderful skill with which Wagner handles the theme, working it up through a superb crescendo to a magnificent climax, with all the splendours of Wagnerian orchestration, after which it dies away again to the ethereal harmonies with which it first greeted the listener.
Act I. The curtain, on rising, discloses a scene of unwonted life on the plain near the River Scheldt, where the stream winds toward Antwerp. On an elevated seat under a huge oak sits _King Henry I._ On either side are his Saxon and Thuringian nobles. Facing him with the knights of Brabant are _Count Frederick of Telramund_ and his wife, _Ortrud_, daughter of the Prince of Friesland, of dark, almost forbidding beauty, and with a treacherous mingling of haughtiness and humility in her carriage.
It is a strange tale the _King_ has just heard fall from _Frederick of Telramund's_ lips. _Henry_ has assembled the Brabantians on the plain by the Scheldt in order to summon them to join his army and aid in checking the threatened invasion of Germany by the Hungarians. But he has found the Brabantians themselves torn by factional strife, some supporting, others opposing _Frederick_ in his claim to the ducal succession of Brabant.
"Sire," says _Frederick_, when called upon by the _King_ to explain the cause of the discord that has come upon the land, "the late Duke of Brabant upon his death-bed confided to me, his kinsman, the care of his two children, _Elsa_ and her young brother _Godfrey_, with the right to claim the maid as my wife. But one day _Elsa_ led the boy into the forest and returned alone. From her pale face and faltering lips I judged only too well of what had happened, and I now publicly accuse _Elsa_ of having made away with her brother that she might be sole heir to Brabant and reject my right to her hand. Her hand! Horrified, I shrank from her and took a wife whom I could truly love. Now as nearest kinsman of the duke I claim this land as my own, my wife, too, being of the race that once gave a line of princes to Brabant."
So saying, he leads _Ortrud_ forward, and she, lowering her dark visage, makes a deep obeisance to the _King_. To the latter but one course is open. A terrible accusation has been uttered, and an appeal must be made to the immediate judgment of God in trial by combat between _Frederick_ and whoever may appear as champion for _Elsa_. Solemnly the _King_ hangs his shield on the oak, the Saxons and Thuringians thrust the points of their swords into the ground, while the Brabantians lay theirs before them. The royal _Herald_ steps forward. "Elsa, without delay appear!" he calls in a loud voice.