Belyas li Noirs, Delyas, Helias
A strong knight who guarded the Spring of the Two Sycamores.
He detested the Knights of the Round Table because he had been denied admittance to their order. He was an excellent jouster, and he unhorsed – among others – Gawaine and Yvain. This prompted a whole host of knights to embark from Arthur’s court to find and challenge Belias. One of them, Sarras, led Lancelot to the spring.
After Sarras himself was defeated, Lancelot jousted with Belias and won, mortally wounding him. Lancelot was later challenged by Briadas, Belias’s brother, and Broadas, his father.
Source
Vulgate Lancelot | 1215-1230