• General Notes

  150 BC
  Beli Mawr was a semi-legendary British king who was probably an historical ruler, though any facts have become so distorted by myth that it is impossible to be certain about the truth concerning him. Beli Mawr derived his name from that of Bel, one of the principal Celtic deities, the god of the sun and of the light.
  
  Beli Mawr (Beli the Great) was an ancestor deity in Welsh mythology. He was the consort of Dôn and the father of Caswallawn, Arianrhod, Lludd and Llefelys. Several royal lines in medieval Wales traced their ancestry to him.
  
  He is usually, though not universally, considered to have derived from the Celtic god Belenus. Historical linguistics suggests that the name Beli may be derived from Bolgios, a name attested as the leader of a Gaulish attack on Macedon in the 3rd century BC. It is related to the Irish "Beltane", modern Gaelic "bealtuinn" (May-day), which comes from Irish "béalteine", reflecting the diphthonging of the initial vowel from Early Irish "beltene", or "belltaine", Proto-Celtic *belo-te(p)niâ (according to Stokes), and means "bright-fire". The Gaulish god-names "Belenos" (*Bright one) and "Belisama" (probably the same divinity, originally from *belo-nos = our shining one) are also from the same source, as was Shakespeare's "Cym-beline".
  
  However, it should be noted that in Medieval Welsh tradition, Beli Mawr is often given the patronymic ap Manogan and his father was noted as Manogen Druid Eneid. This appears to derive from a textual garbling of the name of a real historical figure, Adminius, son of Cunobelinus; after being transmitted through the Roman authors Suetonius and Orosius, this name became Bellinus filius Minocanni in the medieval Welsh text Historia Brittonum. Thus, although Beli became a separate personage in medieval pseudohistory from Cunobelinus (Cymbeline), he was generally presented as a king reigning in the period immediately before the Roman invasion; his "son" Caswallawn is the historical Cassivellaunus.
  
  Beli also appears in Geoffrey of Monmouth's Historia Regum Britanniæ as Heli.
  (Wikipedia)
  

Details of The Great's family with Don verch Mathonwy