It will be interesting to compare this story with the version by Malory. The differences are characteristic of the distance between the colder ideals of Malory and the warmer and more human age of Wagner.
Once upon a time a brave knight of Brittany went across the English Channel to the court of King Mark of Cornwall. The knight was noted for his valiant deeds, so the King was right glad to welcome him and attach him to his retinue. The knight also was willing to tarry, for the King had a sister who because of her beauty was called the "White Lily." Indeed, the knight had fallen deeply in love with this fair Princess, and so he was overjoyed when at length he found that his love was returned. He obtained the King's consent to make her his wife; and after a splendid ceremony the knight and his lady set sail for their castle in Brittany. Fate had so smiled upon them, that they thought themselves the happiest people in the whole world, and that none had been so favoured as they.
But after a few short months of wedded life the knight fell sick and died. The poor bride was broken-hearted, and although a little boy was presently given to her, the child did not assuage her grief. Instead he reminded her constantly of the husband she had lost. She called the boy's name Tristan, which means "sadness."
Realising that she would soon follow her beloved husband she entrusted the boy to a trusty knight, Kurneval by name, to be taken over to her brother in Cornwall. Shortly afterward she died, and the little orphan was conveyed to his uncle as the mother had desired.
King Mark was without wife or children of his own, so he gladly received Tristan into his lonely home. He brought him up as his own son, and publicly proclaimed him heir to the throne of Cornwall.
Tristan grew rapidly in beauty and strength, finding so especial a delight in horsemanship and knightly warfare, that by the time he was fifteen he could joust with the best of the knights. Courteous in speech and bearing was he, likewise, for he had been carefully trained by the knight Kurneval. And so, when the time of his knighting had arrived, Sir Tristan was already famed for his chivalry and prowess alike. His name became a proverb for true knighthood, and there was no man in Cornwall who could stand against him.
A few years before this time, King Mark had been defeated in battle by the King of Ireland, and had promised to pay him a yearly tribute. Each year since that defeat the tribute had been collected by Sir Morold a gigantic knight whom all men feared because of his courage and cruelty. His demands grew heavier, year by year, until at last they became so great that the whole country groaned. Thus it went on until Tristan had become a knight, when eager for some splendid service to prove his spurs, he resolved to put an end to this oppression. So he challenged the huge warrior to mortal combat.
The challenge was promptly accepted, Morold liking nothing better than a fight, though—as he expressed it—he greatly feared this rash youth would not last long enough to get his blood warm. King Mark also was fearful of the fate of his foster-son, but the word had gone forth and could not be withdrawn.
The day came for the conflict, and many anxious spectators assembled to watch the champions fight—the one for the honour of Ireland, the other for the freedom of Cornwall. But Morold did not enter the lists fairly. Enraged that any one should presume to oppose him, he bore a poisoned spear which he flung at Tristan without warning. It made a slight wound which was unnoticed in the heat of the conflict that immediately began.
The young knight sprang forward with sword drawn and met his towering opponent fiercely but with the most finished skill. Morold soon found that he had met more than his match at sword play, and he tried by his superior strength to beat down his antagonist. But in this also he was defeated, after a thrilling contest. At last growing rash he raised his sword and brought it about with a terrific swish that would certainly have cut Tristan in two, if he had not leaped nimbly backward. Before the Irish knight could recover himself, Tristan sprang forward again and by one swift stroke cut his head from his body.