Beli Mawr

In the corpus of Middle Welsh tradition and medieval pseudohistorical texts, Beli Mawr functions as a deep-seated ancestral forebear and legendary king incorporated into genealogies that legitimate ruling houses (for example, links to the House of Gwynedd). He is named as the father of figures such as Arianrhod, Lludd Llaw Eraint, Llefelys, Cassivellaunus/Caswallawn, and Afallach. Medieval texts also preserve a separate but often-conflated figure recorded as "Beli son of Manogan" (derived in transmission from names such as Cunobelinus and Adminius); later medieval and modern writers sometimes conflate these figures, and Geoffrey of Monmouth renders a parallel king as Heli whose name is restored to Beli in Middle Welsh translations.

Medieval genealogies, the Welsh Triads, and Mabinogi-related material present Beli Mawr as an ancestral and kingly figure embedded in pedigrees and narrative lineages but provide no consistent or detailed physical description. The primary texts record relationships, descent, and status rather than corporeal features. Modern speculative summaries that identify Beli with Belenos occasionally ascribe radiance or "shining" etymologies, but such physical attributes are not attested as descriptions in the cited medieval sources.

In the medieval material supplied, Beli Mawr's primary function is genealogical and legitimatory: he is an eponymous progenitor and legendary king whose value lies in anchoring royal lineages to a heroic past. He is located in sequences of pre-Roman and legendary British rulers and is named as parent to several mythic figures. Secondary modern and scholarly hypotheses propose an onomastic connection with the continental deity Belenus/Belenos and, on that basis, attribute possible solar or healing associations; the supplied sources present these as interpretive reconstructions and not as direct medieval attestations of supernatural powers.