The “Last Tournament” in Tennyson’s Idylls of the King.
As Arthur was away from court, Lancelot was appointed its judge. Disillusioned and bored, Lancelot refused to enforce the rules of the tournament or even the basic customs of chivalry, and the festival was a disaster.
Tristan (Tristram) was chosen as the winner and, as the crowning calamity, he refused to award the crown to any of the women in the audience – even though his wife, Isolde of the White Hands (Isoud La Blanche Mains), was among them – saying that his true love was not present.
The tournament marked the beginning of the rapid downfall of Arthur’s kingdom.
Source
Idylls of the King | Lord Alfred Tennyson, 1859-1886