The Second Branch is a story about how a war starts, told by someone who knew exactly how wars start. A man is insulted at a wedding. The insult is paid for, generously and in full. The payment is accepted. And two islands are depopulated anyway, because somebody remembered, and because the compensation included a cauldron that brought dead soldiers back.
It ends with seven survivors sitting in a room with a severed head for eighty years, and the head is good company.
The marriage
Bendigeidfran son of Llŷr — Brân the Blessed — was crowned king of the Island of the Mighty, and he was so large that no building had ever been made that could hold him.
He was sitting on the rock at Harlech when thirteen ships came up from Ireland. Matholwch, king of Ireland, had come to ask for his sister Branwen, one of the three chief women of the island, so that Ireland and Britain might be stronger together. The offer was accepted at once, and the wedding feast was held in tents at Aberffraw, because there was no house that would take Brân.
Nobody consulted Efnysien.
He was Brân and Branwen's half-brother, and the tale's description of him is blunt: he was a man who would make trouble between two brothers when they were fondest of each other. His full brother Nysien was the opposite, a man who could make peace between armies. Efnysien came back from wherever he had been, found his sister married without his consent, and went to where the Irish horses were stabled.
He cut their lips back to the teeth, their ears down to their heads, their tails to their backs, and where he could get hold of the eyelids he cut those to the bone.
Buying it back
Matholwch heard about it while he was eating and got up to leave. The messengers who caught him made the case that his hosts were more insulted than he was, since the outrage had been done to a guest at their own feast.
So Brân paid. A sound horse for every ruined one. A silver staff as thick as his little finger and as tall as Matholwch himself. A gold plate as broad as his face.
And then, because the Irish king's face still had not changed, he gave him something more: the Cauldron of Rebirth. A man killed today, thrown into that cauldron, would be as good as ever by tomorrow — except that he would never speak again.
The cauldron's history is told at the feast, and it is worth having. It had come from Ireland in the first place. A giant and his wife came out of a lake carrying it; she gave birth to a fully armed warrior every six weeks; their sons became so intolerable that the Irish built an iron house, packed it with them, fed the outside with charcoal, and worked the bellows until the walls were white — and the giant and his wife broke out through the glowing metal and escaped to Britain, where Brân took them in.
Matholwch, in other words, was given back the weapon his own country had failed to destroy. Everyone at that table was satisfied with the settlement.
Ireland
Branwen went to Ireland and was honoured there, and in the first year she bore a son, Gwern.
In the second year the men of Ireland began talking about the horses. The insult had been paid for, but it had not been avenged, and the king's own men would not let it go. So Matholwch let them have their way. Branwen was driven out of the royal chamber into the kitchen and set to cook, and the butcher was told to strike her on the ear every day after he had finished cutting meat. Ships from Britain were banned, and anyone travelling from Ireland was to be imprisoned so that no word could cross.
She stood at the kneading trough for three years, and she raised a starling on the edge of it, and taught it to talk. She told it what her brother looked like, wrote a letter about her situation, and tied it under the bird's wing.
The starling found Brân in Arfon and settled on his shoulder, and he read the letter and raised the muster of the entire island.
The mountain in the sea
He crossed with a fleet and walked, because the water between Britain and Ireland was shallow then and there were only two rivers in it. His musicians travelled on his back.
The Irish swineherds on the coast reported to Matholwch that a forest had appeared on the sea where no tree had ever grown, with a mountain beside it, and on the mountain a high ridge and a lake on either side of the ridge, and the whole thing was moving.
Nobody in Ireland could interpret it, so they sent to Branwen, and she told them. The forest is the masts of the ships. The mountain is my brother wading, because no ship will hold him. The ridge is his nose and the two lakes are his eyes.
The Irish pulled back across the Shannon and broke the bridge behind them. Brân lay down across the river and his army walked over him, and the sentence he says while doing it became a Welsh proverb: let him who would be a leader be a bridge.
Peace, and the flour bags
Ireland sued for peace and offered terms designed to be irresistible. They would build a house big enough to hold Bendigeidfran, which had never been done, and they would give the kingship of Ireland to Gwern — Branwen's son, and therefore Brân's nephew.
They built the house. Then they hung a hundred leather bags from the pillars, and in each bag they put an armed man.
Efnysien came in ahead of the others, looked around the building with the eye of a man who expects to find something, and asked what was in the first bag.
Flour, he was told.
He put his hand on it, found the head inside it, and squeezed until his fingers met in the bone. Then he went round all two hundred pillars and did the same, singing to himself, and by the time the company arrived every bag held a dead man and nobody knew.
The fire
The peace was made. Gwern was given the kingship and passed from hand to hand round the hall to be admired, from his uncle to his uncle, a small boy being loved by everybody.
Efnysien said that his nephew should come to him too, since nobody had thought to bring him. The boy came gladly. And Efnysien picked him up and threw him head first into the fire.
Branwen tried to go into the fire after him and her brother caught her. The hall went up. The Irish lit the cauldron and fed their dead into it all night, and they came out fighting and silent, and the British had no cauldron.
Efnysien, seeing what he had made, hid himself among the Irish corpses. Two Irishmen picked him up and threw him in with the rest. And inside the cauldron he stretched himself until it split into four pieces, and his heart burst with the effort.
That is his atonement, and the tale offers no verdict on whether it settles the account.
Seven men and a head
Seven of the British survived, and one of them was Pryderi from the First Branch and another was Manawydan, Brân's brother, and another was Taliesin.
A spear had gone into Brân's foot, the point poisoned, and he understood what that meant before anyone had to tell him. The orders he gave were exact.
Take my head off. Carry it to London, to the White Hill, and set it in the ground looking out across the water towards France; nothing that comes as a plague will reach this island while it lies there. The journey is going to be long. Seven years at Harlech first, with Rhiannon's three birds singing over the sea. Then eighty at Gwales, where I shall be no worse a companion than I have been with my body on. And you will remember nothing you have lost — not until somebody opens the door on the Cornwall side. After that you cannot stay another hour.
Branwen came ashore at the mouth of the Alaw in Anglesey, looked back at Ireland and then at Britain, said that two good islands had been destroyed because of her, and her heart broke. They buried her in a four-sided grave on the riverbank.
In Ireland, five pregnant women had survived in a cave, and their five sons repopulated the island and married one another's mothers and divided the country into five, which is why Ireland has the provinces it has.
The seven men reached Harlech and sat down to eat, and three birds began singing over the sea, and every song they had ever heard was harsh next to it; and they sat for seven years. Then they went to Gwales, into a hall with three doors, two open and one shut, and stayed eighty years without remembering a single sorrow, or the loss of the country, or anything at all that had happened to them.
Then Heilyn son of Gwyn said he would be a poor man if he did not find out what was behind that door, and opened it. And everything came back at once — every death, every friend they had lost, the whole thing as raw as the hour it happened, and above all the loss of their king. They could not rest after that. They went to London and buried the head.
Where this comes from
This is the Second Branch. Two late-medieval Welsh manuscripts carry it — the White Book of Rhydderch, from around the middle of the fourteenth century, and the Red Book of Hergest, from around the turn of the fifteenth — and the writing of it is put a couple of hundred years before either. "Mabinogion" as a name for the collection dates only from the nineteenth century.
The Welsh Triads carry a sequel that the Branch itself only gestures at. Putting the head into the White Hill counts, in that catalogue, as one of the three lucky burials of the island; taking it out again counts as one of the three disastrous unearthings. The excavator was Arthur, whose stated reason was that he did not care to have Britain protected by anything except himself.
A modern claim needs separating out here, because it circulates constantly. Brân's name means raven, his head is buried at the Tower of London, and ravens are kept at the Tower — from which people conclude an unbroken tradition. There is no medieval source connecting the birds to Brân, and the documented history of the Tower ravens does not run back anywhere near this far. It is a nineteenth- or twentieth-century synthesis, and an appealing one.
What the Branch is arguing
That compensation does not end a grievance. Brân's settlement is legally impeccable and materially generous, and Welsh law took such payments extremely seriously. It still fails, because Matholwch's men decide that a debt paid is not an insult erased. Everything after that is consequence.
That the cauldron is the problem. The most generous item in the settlement is what makes the war unwinnable. Given as an act of reconciliation, it comes back as an army of silent dead. A story composed in a Wales that knew about Norman power might reasonably be interested in the idea that the gift you give a neighbour is the weapon you meet later.
That memory is the wound. The eighty years at Gwales are not an afterlife and not a reward. They are a suspension of grief, and the moment the door opens the grief is undiminished. The Branch's last act is a man deciding he would rather know.
Points often asked about
Is Brân a god? He is a king in the text — enormous, but a king, with a genealogy and a court. Some scholars read a euhemerised divine figure behind him, on the strength of his size, his talking head, and the Irish parallels. The tale itself makes no such claim, and neither should a reader.
Is Bedd Branwen her grave? There is a Bronze Age burial site on the Alaw in Anglesey that carries her name, excavated in the 1960s and producing genuine cremation urns. It is roughly two thousand years older than any possible setting for the story. The name is folk tradition attached to a monument, which is how most such identifications work.
Why does Efnysien do any of it? The tale gives him a temperament rather than a motive. He is a man constitutionally unable to leave a situation alone, and the author uses him as the mechanism by which two acts of statesmanship are destroyed. His death is the only act of repair in the story and it kills him.
Do the birds of Rhiannon connect to the First Branch? They are named for her and their singing is elsewhere said to wake the dead and put the living to sleep, but they are not explained here or anywhere else. They are one of the Branches' loveliest loose ends.
Why bury the head facing France? Because that is where invasion comes from, and the head is a border defence. The talking head as protective object has close Irish and wider Celtic-language parallels, and this is the fullest surviving example in Welsh.
Continue with Brân the Blessed, Taliesin among the seven, the First Branch at Pwyll and the Otherworld, the cauldron of the Dagda for the Irish vessel this one is often compared with, and the Celtic hub.