THE FOURTH BRANCH
Math Son of Mathonwy
Math, son of Mathonwy was lord over Gwynedd.
Math could not live without keeping his feet in the lap of a maiden, unless war prevented him. The maiden to whom this task fell was Goewin, so Goewin was with Math at all times.
In Math’s court were his nephews, Gwydion and Gilfaethwy. Gwydion realised one day that his brother, Gilfaethwy was smitten with love for Goewin, so he hatched a plot to help him.
Gwydion went to Math and told him that Pryderi had come into possession of domesticated pigs, the like of which had not been seen, and offered to go and ask Pryderi to give them to Math.
Gwydion arrives at Pryderi’s court and offers to tell a story after the feasting, as he was the best teller of stories anyone had ever heard. Pryderi is impressed with Gwydion's storytelling prowess, and enjoys talking with him.
As Gwydion feels Pryderi's regard for him, he decides to reveal his purpose, and requests the pigs for Math. Pryderi explains that when they were given to him by Arawn of Annwn, it was under the condition that he would not give them to any until they have doubled their number. So Gwydion vows to find a way around this problem, and offers an exchange for them instead.
By magic, Gwydion conjures twelve stallions and twelve greyhounds by using toadstools, with all their finery in gold upon them. He offers them to Pryderi in exchange for the pigs so that he is neither giving them or selling them, and thus keeps his word to Arawn.
Pryderi accepts, and Gwydion and his men depart with the swine. They need to hurry, for the spell will not last long before the horses and dogs become toadstools again.
Soon enough, Pryderi and a great army are coming upon their heels. Gwydion sends a messenger to Math, asking him to send his forces to engage Pryderi, whilst Gwydion goes to Gilfaethwy to inform him that Goewin is now available. She is forced to spend the night with Gilfaethwy against her will.
After a great battle, it is agreed that Gwydion should face Pryderi alone, as it was he who created the wrong-doing. Gwydion then slays Pryderi using his magic and enchantment.
When Math goes to Goewin to put his feet in her lap after the battle, she tells him she is no longer a maiden and explains what happened. Math decides to marry Goewin and find another lap-maiden, but first he visits punishment on Gwydion and Gilfaethwy.
He turns one into a hind and the other into a stag, and sends them into the forest to copulate together for a year. When they return, they bring a fawn, which Math turns into a boy. He turns the hind into a wild boar, and the stag into a wild sow, and sends them out for a further year. They come back with another offspring who is turned into a boy, and the boar is turned into a she-wolf and the sow into a he-wolf, and another year goes by. They return with a wolf cub that Math turns into a third child, and so it is that Gwydion and Gilfaethwy have three sons together. And that was the end of their punishment, they were made men again.
Now Math sets about finding a new lap-maiden, and Arianrhod is summoned as a worthy contender. Math requests her to step over his magic staff to test her virginity, but as she does so, two objects fall from between her legs. One is a fine boy child, the other is so small, none see it except Gwydion, who quickly gathers it and hides it away.
The boy is named Dylan, a child of the sea. Meanwhile, the other object was also a boy child, and Gwydion has him wet-nursed until he grows. One day, Gwydion takes him to Arianrhod’s court to ask her to name him, but she refuses, saying that the boy brings shame upon her. She swears that the boy will get no name unless he gets it from her, and that she will not give it.
So Gwydion uses his magic to conjure a ship and to disguise himself and the boy. He sets up work making shoes on the boat until all are talking about his shoes being the finest ever seen. At last, Arianrhod comes down to the ship to see the shoes and have her feet measured.
Meanwhile, the boy is taking slingshots at a wren and hits it. Seeing this, Arianrhod says “the fair one has a deft hand”. At that, Gwydion reveals their identity and that she has named her son, Lleu Llaw Gyffes (Fair Deft-hand).
Arianrhod is furious, and swears he shall never have the tools of a warrior unless she gives them, and this she will never do.
Some time in the future, when Lleu Llaw Gyffes is ready for arms, Gwydion takes him to Arianrhod’s stronghold, disguised, where they seek a bed for the night. In the early hours of the morning, Gwydion conjures by magic the sounds of a great war-band outside the stronghold in the dark. Fearing they are under attack, Arianrhod comes and begs them to help defend the stronghold.
Gwydion agrees and asks her to fetch arms for the boy and array him, whilst her maid does the same for him. When she has finished putting the last piece of armour upon Lleu, the clamour stops and Gwydion reveals their true identities.
Arianrhod is furious again, and vows he will never have a wife who is of any of the races on the earth.
Gwydion goes to Math and together they conjure the most beautiful maiden to be a wife for Lleu out of flowers, and they call her Blodeuwedd. Then Lleu Llaw Gyffes is given his own lands where he lives with his wife.
One day, he travels to visit Gwydion and Math, and whilst he is away, a stranger called Gronw Bebyr passes the stronghold and is invited in by Blodeuwedd. They fall in love, and with Lleu away, sleep together for some nights.
Then they hatch a plan to kill Lleu so that they can be together, and this means Blodeuwedd must first find out from Lleu how he can be killed.
One day, Blodeuwedd asks Lleu Llaw Gyffes how he can be killed on pretence of fear he might one day be at risk. He reassures her it is most unlikely and explains that he can only be killed by a blow from a spear a year in the making, and only made when people are at worship.
Additionally, he cannot be slain in a house or outside, and he cannot be slain on horseback or on foot. He explains that the only way would be if he was half way in a bath built outside with a vaulted roof over it so that he was half under the roof, and with one foot in the bath and the other over a goat, and whilst in this stance, he would need to be hit with the said-mentioned spear.
Blodeuwedd sends word to Gronw and he sets to work on the spear. When it is ready, Blodeuwedd asks Lleu to show her how he would need to be standing in order to be slain, and he agrees. With Gronw hiding nearby, Lleu goes to the bath with the vaulted roof that Blodeuwedd has set up by the river bank, and places a foot in the bath and the other on a goat. At that moment, Gronw throws the spear.
As he is hit, Lleu Llaw Gyffes transforms into an eagle and flies away.
News reaches Math’s court, and Gwydion sets out to find Lleu. Gwydion travels the country until one day he hears of a man whose sow is acting strangely.
Upon opening her pen every morning, she sets out at a fast pace and goes no-one knows where. The next morning Gwydion sets out to follow her until he finds her feeding under a tree. He sees she is feeding on maggots and rotten flesh. He then sees an eagle in the top of the oak tree, shaking itself, and the maggots and rotten flesh are falling from it.
Gwydion sings some magical words, and the eagle comes down the tree until he alights on Gwydion’s knee where Gwydion strikes him with his staff, so that he becomes a man again.
Lleu Llaw Gyffes goes away to mend and become well, whilst Gwydion sets off after Blodeuwedd and Gronw. He chases Blodeuwedd until he catches her and transforms her into an owl.
As reparation for the blow, Lleu Llaw Gyffes demands that Gronw face the same blow from him that was delivered earlier. They each stand on the river bank where the other stood before, but Lleu allows Gronw to hold a great stone between himself and the blow.
Nevertheless, Lleu’s spear goes clean through the stone and slays Gronw. And that is why there is a great stone with a hole through it on the bank of the river Cynfael in Ardudwy to this day.