E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Natural daughter of Guendolen and King Arthur. Arthur swore to Guendolen that if she brought forth a boy, he should be his heir, and if a girl, he would give her in marriage to the bravest knight of his kingdom. One Pentecost a beautiful damsel presented herself to King Arthur, and claimed the promise made to Guendolen. Accordingly, a tournament was proclaimed, and the warder given to Gyneth. The king prayed her to drop the warder before the combat turned to earnest warfare, but Gyneth haughtily refused, and twenty knights of the Round Table fell in the tournament, amongst whom was young Vanoc, son of Merlin. Immediately Vanoc fell, the form of Merlin rose, put a stop to the fight, and caused Gyneth to fall into a trance in the Valley of St. John, from which she was never to awake till some knight came forward for her hand as brave as those which were slain in the tournay. Five hundred years passed away before the spell was broken, and then De Vaux undertook the adventure of breaking it. He overcame four temptationsfear, avarice, pleasure, and ambitionwhen Gyneth awoke, the enchantment was dissolved, and Gyneth became the bride of the bold warrior. (Sir Walter Scott: Bridal of Triermain, chap. ii.)