His name perhaps derived from Bel or Beli.
Belin, Belins, Bellinus, Belyns
When his father, King Dunwallo, died, Belinus and Brennius contended for the throne. After many battles, the brothers reached a truce and divided the island at the river Humber, with Belinus the higher king.
Five years later, they went to war again. Brennius was aided by Norweigans, but was still defeated and driven off the island. During the same period, Belinus subjugated Denmark. He was eventually reconciled with his brother. Together, they conquered Gaul and Rome. Brennius remained to rule Rome whiel Belinus returned to Britain. His son Gurguint Barbtruc succeeded him.
When Arthur faced war with Rome, he used Belinus's example as justification and inspiration for his own campaign. In the fourteenth-century Short Metrical Chronicle, with its confused chronology, Belinus is succeeded by Hengist. He may be reflected in Welsh legend by Beli the Great.