The Mabinogion Decoded: How Ancient Gods Were Disguised as Medieval Kings and Queens

Written by Simon Williams

There is a particular pleasure in reading a text that is hiding something.

Not hiding it maliciously, and not hiding it completely. But holding something back just behind the surface of the narrative, visible to those who know where to look, invisible to those who do not. A text that rewards second readings, that reveals more the more you understand about the world it came from, that accumulates depth rather than exhausting itself in a single encounter.

The Mabinogion is that kind of text. And once you know what it is hiding, you cannot read it the same way again.

The Mabinogion is the foundational collection of Welsh mythology, a compilation of medieval tales drawn from two manuscripts, the White Book of Rhydderch and the Red Book of Hergest, written down in the thirteenth and fourteenth centuries. It contains eleven main tales, ranging from the Four Branches of the Mabinogi, which are the core mythological material, through Arthurian stories and independent tales, to the romances that show the influence of French literary culture on the Welsh tradition.

Reading the Mabinogion as a straightforward collection of medieval stories is entirely valid and genuinely rewarding. The tales are beautifully constructed, emotionally complex, and full of moments that retain their power across a thousand years.

But reading it as a surface is to miss what I consider its most extraordinary dimension: the ancient mythology that the medieval scribes preserved beneath the courtly surface, visible in the details that do not quite fit the medieval frame, in the characters who behave according to rules that no medieval courtier would follow, and in the supernatural logic that operates independently of and occasionally in contradiction to the Christian framework that overlies it.

I explore this world in full in my book Welsh Myths and Legends: Fairies, Hounds and Holy Wells, available on Amazon here: https://amzn.eu/d/0dBHSPl0. But let us begin with the process by which ancient gods became medieval characters.

How Gods Become Kings: The Process of Euhemerisation

The technical term for what happened to the Welsh gods in the Mabinogion is euhemerisation, a word derived from the ancient Greek writer Euhemerus, who argued that the gods of mythology were originally historical human beings whose remarkable deeds had been inflated into divine status over time.

In the Welsh case, the process worked in something like the opposite direction. The divine figures of the ancient Celtic world were not inflated into gods from human origins. They were deflated from divine status into human characters, their mythological functions preserved but their supernatural identities obscured, by the medieval Christian scribes who committed the oral tradition to writing.

The reasons for this were practical rather than malicious. The oral tradition preserved by the Cyfarwyddiaid contained material that was explicitly pagan in origin, stories of gods and goddesses, magical objects, the Otherworld, and the complex supernatural ecology of pre-Christian Wales. Committing this material to writing in a Christian monastic context required a degree of accommodation: the gods had to be made acceptable, which meant making them human.

The accommodation was accomplished with considerable skill and considerable subtlety. The divine figures were not stripped of their powers or their significance. They were relocated into a human social framework, given royal titles and genealogies, and placed in narrative contexts that made sense within a medieval Welsh political world. Their supernatural qualities were retained but reframed as exceptional human abilities, magical skills, or the workings of an unnamed divine providence rather than the direct expression of their own divine nature.

The result is a text that operates simultaneously on two levels: the surface level of medieval courtly narrative, with its kings and princes and their political dramas, and the deeper level of ancient mythology, with its gods and supernatural forces and the cosmological dramas those forces enact.

Reading the Mabinogion with both levels in mind is one of the most intellectually satisfying experiences that Welsh mythology has to offer.

The Four Branches: Where the Gods Are Hiding

The core mythological material of the Mabinogion is contained in the Four Branches, a sequence of four interconnected tales that share characters, settings, and a complex of themes that suggest a single, originally coherent mythological system beneath their medieval surface.

The First Branch: Pwyll, Prince of Dyfed

The First Branch introduces Rhiannon, who is widely understood by scholars as a development of an earlier Celtic horse goddess, connected to the Gaulish deity Epona. The evidence for this identification lies not in any explicit statement in the text but in the pattern of details: her association with a white horse that cannot be outrun, the bag that can never be filled, the birds whose singing causes three years of sleep, and above all the dignity and self-sufficiency that characterise her throughout her story. These are the attributes of a deity, not a noblewoman.

The First Branch also establishes the relationship between the human world of Dyfed and the Otherworld of Annwn, with Pwyll spending a year in Annwn in the guise of its ruler and thereby establishing the connection between the two kingdoms that runs through all four branches. This exchange of identities between a mortal ruler and the king of the Otherworld is not a courtly political manoeuvre. It is a myth about the relationship between the living world and the world of the dead, encoded in the narrative of a diplomatic arrangement between neighbouring kingdoms.

The Second Branch: Branwen, Daughter of Llyr

The Second Branch is, on its surface, a tale of political alliance, diplomatic breakdown, and catastrophic war between Britain and Ireland. Beneath that surface, it preserves some of the oldest mythological material in the entire collection.

Brân the Blessed, the giant king of Britain, possesses a cauldron of rebirth that can restore the dead to life, though without the power of speech. The cauldron is almost certainly connected to the magical cauldron of Annwn that Arthur raids in Preiddeu Annwfn, and both are almost certainly precursors of the Holy Grail of later Arthurian tradition. The chain of transmission from a Welsh Otherworldly cauldron to a Christian sacred vessel is one of the most fascinating stories of mythological transformation in European literature.

Brân himself is a divine figure barely concealed beneath his royal title. His size, his impossibility of containment, the supernatural properties he possesses, and the manner of his eventual death, which leaves his still-living severed head providing companionship and counsel to his followers for decades, all mark him as something considerably more than a king. He is a god in a king's clothing, and the medieval scribes who wrote his story down seem to have understood this even as they accommodated it to their narrative framework.

The Third Branch: Manawydan, Son of Llyr

The Third Branch is the quietest and in some ways the strangest of the four. It follows Manawydan, Pryderi, and their wives through a series of displacements and enchantments, culminating in the emptying of Dyfed and the recovery of its people through a confrontation with a supernatural bishop who turns out to be responsible for the enchantment.

The stripping of a land of its people and its fertility, and the hero's quest to restore it, is one of the oldest mythological patterns in existence, found in traditions from Mesopotamia to Ireland. The Mabinogion version preserves this pattern while thoroughly disguising its divine dimensions, presenting the emptying of Dyfed as the consequence of a personal revenge rather than a cosmic catastrophe. But the pattern itself, and the ritual logic that drives the resolution, speaks to something much older than the medieval narrative frame.

The Fourth Branch: Math, Son of Mathonwy

The Fourth Branch is the most mythologically dense of the four, and the one that contains the highest concentration of divine figures barely concealed beneath their human titles.

Math ap Mathonwy is an ancient figure, bound by a magical condition that connects him to older traditions of sacred kingship in which the ruler's magical potency was linked to and dependent on specific conditions of ritual purity. His footholder requirement, the need to keep his feet in the lap of a virgin except during times of war, is a strange detail that makes no sense within a purely medieval courtly framework but makes considerable sense as a survival of sacred kingship ritual.

Gwydion is one of the great trickster-magicians of world mythology, a figure whose shape-shifting, storytelling, and manipulation of reality mark him as a divine being of considerable power regardless of his human title. His creation of Blodeuwedd from flowers, his transformation of his brother and himself into animals as punishment for their crimes, and his ultimate restoration of Lleu from eagle form to human form are all acts of divine magic that no medieval Welsh wizard could actually perform.

And then there is Arianrhod, whose name and whose associations with the silver wheel and the star-fort of Caer Arianrhod connect her to cosmic and stellar mythology that predates the medieval period by a very long way.

The Independent Tales: Arthur Before Camelot

Beyond the Four Branches, the Mabinogion contains several independent tales that provide crucial evidence for the pre-Galfridian Welsh Arthur, the Arthur who existed in Welsh mythology before Geoffrey of Monmouth's Historia Regum Britanniae transformed him into a European literary superstar.

Culhwch and Olwen is the oldest Arthurian story in any language, and the Arthur it presents is wildly different from the courtly king of later romance. He is a warlord surrounded by an extraordinary company of superhuman heroes, hunting a monstrous enchanted boar across the length of Wales and Ireland, and achieving tasks that have no parallel in any courtly narrative. This is the Arthur who belongs to Welsh mythology: a figure of the wild places, connected to the supernatural ecology of the landscape, operating by rules that the French romancers never understood and therefore never incorporated.

The tale of Culhwch and Olwen also preserves the longest list of Arthur's companions in any Welsh source, a remarkable catalogue of figures with supernatural abilities that reads less like a roster of knights and more like a pantheon of minor deities, each with a specific power associated with a specific domain of the natural or supernatural world.

I explore the full dimensions of the Welsh Arthur in my article on Welsh mythology and King Arthur and in connection with the broader Arthurian tradition available through our course The Historical Search for King Arthur.

The Manuscripts: How the Stories Were Preserved

The physical vessels through which the Mabinogion reached us deserve a moment's attention, because the story of the manuscripts is itself part of the story of Welsh cultural survival.

The White Book of Rhydderch, compiled around 1350, and the Red Book of Hergest, compiled between approximately 1382 and 1410, are the two primary sources for the Mabinogion as we have it. Both are large, carefully produced manuscripts that represent a significant investment of resources and effort by the Welsh learned class of the fourteenth and early fifteenth centuries.

The timing is significant. The late fourteenth and early fifteenth centuries were a period of considerable political and cultural pressure for Wales, culminating in the Owain Glyndŵr uprising of 1400 to 1415, the last major Welsh attempt to re-establish political independence from England. The compilation of the great Welsh manuscripts in this period was not coincidental. It was an act of cultural preservation, a deliberate effort to commit the Welsh oral tradition to writing before it could be further eroded by political and cultural displacement.

The Cyfarwyddiaid had maintained the tradition in its oral form for centuries. The scribes of the fourteenth century gave it a written form that would survive the pressures that the oral tradition could not indefinitely withstand. Between them, the storytellers and the scribes achieved something remarkable: the preservation of a mythological tradition that predated Christianity, that had survived Roman occupation, Anglo-Saxon expansion, and Norman conquest, and that arrived in our hands still recognisably itself despite a thousand years of accommodation and adaptation.

Reading the Mabinogion With New Eyes

I want to close with a practical suggestion for anyone who wants to explore the Mabinogion with the decoding framework this article has provided.

When you read the Four Branches, pay attention to the moments that do not quite fit the medieval frame. The details that are too strange to be courtly decoration and too specific to be random invention. The magical conditions and the ritual obligations and the supernatural consequences that operate according to their own logic rather than the logic of the narrative around them.

These are the moments where the older mythology is showing through the medieval surface. They are the traces of the divine figures beneath the royal disguise, the mythological patterns beneath the political narrative, the ancient cosmological drama beneath the story of kings and their dynastic concerns.

Pay particular attention to what the female figures do and refuse to do. Rhiannon who cannot be caught until she chooses to be caught. Arianrhod who retreats to her island and refuses. Blodeuwedd who demands her own freedom regardless of what she was made for. These are not incidental characters in someone else's story. They are the central figures of a mythological system in which female agency and female refusal carry enormous symbolic weight.

Pay attention to the Otherworld. Every time a character crosses a boundary, enters an enchanted space, encounters a figure of impossible beauty or impossible power, or finds themselves in a landscape that operates by different rules from the one they came from, you are in the presence of Annwn and its logic, the older Welsh understanding of the world as layered rather than singular, permeable rather than fixed.

And pay attention to the animals. The Mabinogion is full of animals with supernatural significance: the white boar and the white stag, the red-eared hounds of the Otherworld, the eagle that Lleu becomes in his transformation, the owl that Blodeuwedd is transformed into. In the older mythology these animals were not symbols. They were manifestations of divine power in natural form, the gods and goddesses of the pre-Christian world still present in the landscape in the only forms the medieval narrative would permit them.

The Mabinogion is hiding its origins in plain sight. Once you know where to look, the ancient mythology is everywhere.

If you want to explore that mythology in its full depth, my book Welsh Myths and Legends: Fairies, Hounds and Holy Wells is where the investigation continues. Get your copy on Amazon here: https://amzn.eu/d/0dBHSPl0

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