Little is known about this Prince of Brittany. Late tradition calls him a son of King Aldrien, and the chronology certainly fits, though he must have been somewhat older than his young bride, Rheinwylydd. As one of the many daughters of the powerful Amlawdd Wledig, marriage to this lady made Bican brother-in-law of High-Queen Igerna of Britain and eventually uncle of the High-King Arthur.
Bican was a famous warrior in Brittany, as shown by his epithet 'the Knight,' and though he was keen for his two sons, Illtud and Sadwrn, to have a good education - sending them to study under their uncle, St. Garmon (later Bishop of Manaw) - he must have been very proud when they both hose to follow him in his military career. Nothing at all is known of his later life though, presumably, he stayed in Brittany while the rest of the family settled in Wales.