Sir Segwarides was a Saracen Knight from the Middle East. He was the son of King Esclabor and brother of Sirs Palomides and Safir, but was converted to Christianity well ahead of them. Early in his career, he fell in love with the Lady of Roestoc (possibly in Hertfordshire); but when she rejected his advances, Segwarides’ passions forced him to lay siege to her castle. She was successfully defended by Sir Gawain.

Segwarides later married, but was unfortunate in having a wayward wife who entered into a passionate affair with Sir Tristram at the Cornish Court, some time before his adventures with the Belle Isolde. King Mark also desired Segwarides’ wife and ambushed Tristram on the way to a lovers’ rendezvous. The wounded Tristram still made love to the lady and the blood-stained sheets revealed their affair. Segwarides squeezed her lover’s name from his spouse and sought out Tristram, but was sorely defeated in combat. Later, Sir Bleoberis thought he’d have his wicked way the lady too and made off with her on horseback. The loyal Segwarides pursued them, but was again shamefully beaten. He, however, had the last laugh, when his wife rejected Tristram for turning up too late to challenge Bleoberis first and the couple were reunited.

The cuckolded knight seems to have recognized that the situation had been of his wife’s making and, when he met Tristram again near the Isle of Servage, they decided to bury the hatchet. They joined together with Sir Lamorak to defeat the local ruler, the wicked Sir Nabon le Noire, and, after killing him Tristram, made Sir Segwarides Lord of the Isle.

As a loyal Knight of the Round Table, Sir Segwarides was killed trying to repel Sir Lancelot's rescue of Queen Guinevere from the stake.