Gwydion

Gwydion is a son of Don and a master of magic whose interventions can move from elaborate deception to direct violence. His defining actions bind private desire to public consequence: a plan meant to secure Goewin for his brother Gilvaethwy provokes a war with Pryderi, and Gwydion himself kills Pryderi in the resulting single combat. Elsewhere, his magic helps bring Arianrod’s children into the story and restores Llew Llaw Gyffes from an eagle’s form, making him both an agent of catastrophe and a source of recovery.

Identity and Place at Math’s Court

Gwydion appears as a member of Math son of Mathonwy’s court and as Gilvaethwy’s brother. When Gilvaethwy’s distress over Goewin becomes apparent, Gwydion recognizes its cause and promises to make events turn in his brother’s favor. His response is not to approach Goewin directly: he proposes to cause the rising of Gwynedd, Powys, and Deheubarth, creating a political crisis around the court’s need for the maiden.

Gwydion’s position gives him access to Math, but he works through concealment rather than open petition. He introduces the unfamiliar swine as the occasion for a journey and an exchange, while his actual purpose is to set the larger scheme in motion. The contrast between courtly access and covert action defines his role: he can speak within the structures of power while secretly manipulating what those structures will do.

The Swine and the Deception of Pryderi

Gwydion tells Math that extraordinary animals have come south and identifies them as swine belonging to Pryderi, sent from Annwn by Arawn. He proposes to travel with eleven companions, in the guise of bards, and seek them. At Pryderi’s court, Gwydion asks for the swine. Pryderi says that an agreement prevents him from giving them away until they have doubled in number, so Gwydion offers to arrange an exchange instead of demanding an immediate answer.

The next day Gwydion presents twelve chargers, twelve black greyhounds with white breasts, collars and leashes that appear to be gold, and twelve shields. The horses’ saddles, bridles, and fittings are also made to look like gold. The shields, however, are formed from fungus, and the splendid gifts are an illusion produced by Gwydion’s arts. Pryderi and his advisers accept the exchange, giving Gwydion the swine. As the party departs, Gwydion warns his companions that the illusion will last only until the same hour the following day.

The trick turns a negotiated exchange into the cause of an armed confrontation. After conflict between their followers, Pryderi proposes that the dispute be settled between the two leaders rather than by further loss among their people. Gwydion accepts the single combat. The episode therefore shows the reach and the cost of his deception: the apparent wealth wins the swine, but the bargain draws Gwydion and Pryderi into a fatal reckoning.

The Duel and Its Aftermath

Gwydion and Pryderi arm themselves and fight. Gwydion’s strength and fierceness are joined to his use of magic and charms; together, these enable him to kill Pryderi. Pryderi is buried at Maen Tyriawc, above Melenryd. The men of the South return home in grief, having lost their lord, many of their best warriors, and most of their horses and arms. Gwydion’s victory is thus not a private success: it leaves Pryderi’s people bereaved and materially weakened.

After the duel, Gwydion asks Math to release the hostages given by the men of the South as pledges for peace. Math agrees, and the hostages are freed to follow their people. This act does not undo the death that Gwydion caused, but it marks a limit to the victors’ treatment of the defeated: the captives are not kept in prison once peace has been secured.

Arianrod and the Children

After Math has punished Gwydion and Gilvaethwy for their wrongdoing, he restores them to human form with his magic wand. Gwydion acknowledges the punishment and dishonour and is asked to advise Math about a maiden to seek. He recommends Arianrod, Math’s niece and the daughter of Don. His advice brings Arianrod before Math and leads to a revelation of her children.

When Arianrod steps over Math’s bent wand, a fair, yellow-haired boy appears. As the child cries, Arianrod moves toward the door; another small form is glimpsed, but Gwydion catches it before anyone can see it clearly and conceals it in a velvet scarf at the bottom of a chest by his bed. Math names the first boy Dylan, who is baptized and then plunges into the sea, taking on its nature and swimming like a fish. Gwydion’s quick intervention preserves the second child from immediate notice, though the episode does not describe his subsequent upbringing here.

Restoring Llew Llaw Gyffes

Gwydion’s magic serves a different purpose when he encounters Llew Llaw Gyffes in eagle form. He strikes the eagle with his wand, and Llew returns to his own shape. The restoration reveals the severity of Llew’s condition: he is little more than skin and bone. Gwydion takes him to Caer Dathyl, where physicians from Gwynedd treat him; by the end of the year, he has fully recovered.

Once healed, Llew asks Math for the chance to exact retribution on the person responsible for his suffering. Math affirms that Llew will not be prevented from reclaiming what is rightfully his. Gwydion’s role here is not to resolve the conflict through the same kind of deception that drove the dispute with Pryderi, but to restore the injured man to health and make further action possible. Across these episodes, magic is neither simply a weapon nor simply a remedy: Gwydion’s arts deceive, provoke, kill, conceal, and heal, with consequences that extend well beyond the moment in which he uses them.