Carsibilans, Cassibelans, Cassibilans, Quassibilans
The nephew of Duke Calles and brother of Alibel, Dyonis, and Dion.
His six cousins revolted against Calles, their father. Casibilant and his brothers assisted Calles in the war, in which they were joined by Agravain, Gaheris, and Gareth.
Source
Vulgate Lancelot | 1215-1230