A knight who figures into a variant version of the story of Erec and Enide found in the Prose Tristan.
Senehar killed the Duke of Huiscam, who was Enide’s father, and tried to steal Enide’s inheritances. Erec, Galahad, Bleoberis, and Hector defeated Senahar’s men, captured him, and imprisoned him for life.
Source
Prose Tristan | 1230-1240