Beli and Belenus
The origin of the name Beli is still a matter of debate among scholars. The most popular hypothesis sees the name Beli as a Middle Welsh reflex of the Gaulish and Brittonic theonym Belenus (also attested as a personal name), but a more recent alternative is that proposed by the Celticist John Koch, who suggests that Beli derives from an Old Celtic name Belgius or Bolgios, borne by one of the chieftains who led the Gallic invasion of Macedonia in 280-279 BCE. He therefore proposes that this great leader Belgius came to be regarded as the namesake and ancestor of the powerful British and Gallic tribal group the Belgae, whence would have come the doctrine that Beli was the ancestor of tribal dynasties.
Read more about this topic: Beli Mawr