Ireland during Branwen’s war is first presented as a kingdom seeking an alliance with the Island of the Mighty, then as the country where a diplomatic insult turns into Branwen’s mistreatment and Bendigeid Fran’s invasion. Its story ends in devastation: five pregnant women survive, and their sons grow up to govern and repopulate the land, dividing it into five parts whose names endure.

Marriage and Alliance

Matholwch, king of Ireland, arrives by ship to ask Bendigeid Fran for Branwen’s hand. He presents the marriage as a means of joining the Island of the Mighty and Ireland in an alliance that would strengthen both. Bendigeid Fran receives him, and the two courts agree to the match. The wedding feast takes place at Aberffraw, where Branwen becomes Matholwch’s bride.

After the feast, Matholwch sails home with Branwen from Aber Menei in a fleet of thirteen ships. Her arrival is welcomed with broad public joy. She gives clasps, rings, and royal jewels to the prominent men and noblewomen who visit her, and spends the first year enjoying honour and friendship. During that time she gives birth to Gwern, her son with Matholwch, who is sent to be fostered among Ireland’s leading men.

The Dispute and Branwen’s Treatment

In the second year, resentment rises over the insult Matholwch had received in Cambria and the payment made to him for his horses. His foster-brothers and close supporters openly reproach him, and the resulting tumult leaves him unable to find peace until the grievance is avenged. The retaliation falls on Branwen: she is separated from Matholwch’s chamber and made to cook for the court. The change is stark—the queen who had been honoured on arrival is made to serve in the household, and her position becomes the cause of a wider conflict.

Bendigeid Fran’s Arrival

When word of Branwen’s suffering reaches Bendigeid Fran, he summons the island’s forces and resolves with his council to cross to Ireland. He leaves a group of leaders behind to govern at home, then sails with his host. Near the Irish shore, the army reaches shallow water at the mouths of the Lli and the Archan; the assembled forces cover the sea. Bendigeid Fran carries his provisions on his own back as he approaches the land.

From the shore, Matholwch’s swineherds see what appears to be a forest moving over the sea, beside a mountain with a ridge and a lake on either side. Branwen recognizes the sight as her brother and his fleet: the apparent forest is the ships’ masts and yards, while the mountain is Bendigeid Fran himself. The approaching army’s scale is thus conveyed first through the astonished observers’ description and then through Branwen’s explanation.

Devastation and Repopulation

The war leaves Ireland almost empty. The account names only five pregnant women, sheltering in a cave in the wilderness, as survivors. Their five sons are born on the same night and are raised until they become young men. The sons seek wives, take wives from among the mothers of their companions, and come to govern and repopulate the country.

They divide the land among themselves into five parts. The narrative connects that division directly to the five divisions by which Ireland is still said to be named, making the political geography of the surviving country a consequence of the war’s near-total destruction. The survivors also search the former battlefields and find enough gold and silver to become wealthy.

Narrative Significance

Ireland changes in the story from Matholwch’s realm of diplomatic possibility and Branwen’s honoured new home into the site of her punishment, her brother’s expedition, and the near-extinction of its population. The final account of the five women and their sons shifts the emphasis from the royal conflict to the land’s recovery: its divisions and renewed governance arise from a handful of survivors. The location’s role therefore extends beyond hosting the war; Ireland’s altered population and territorial order record its aftermath.