Belenos (Belinus, Beli)
A Solar deity, he can be seen as a Celtic equivalent of Apollo, and there are various traces of his cult in Britain. In Irish mythology he was Bile, a powerful god of the underworld.
It is thought by some scholars that the festival Beltane has a connection with him, and is phonetically derived from his name. As with many Celtic gods, the name of Belenos becomes denuded into pseudo historical figures with the passing of the centuries. Geoffrey of Monmouth mentions a King Bellin, who rules in Britain and establishes a castle near to the Thames in London. Bellin has a brother called Brennius, and is also the son of Lud and Lleffellys, who rule Britain and France after his death. It has even been suggested that characters in the later Arthurian cycle such as Balin and Balan in Malory’s The Morte De Arthur, are derived from Belenos.
Beli (Beli Mawr), Bran’s Grandfather from Welsh tradition is probably one in the same as Belenos.