To Pryderi, the son of Pwyll, the King of Annwfn sent as gift a drove of swine. Pryderi then had rule in the South, and Math, the son of Mathonwy, had rule in the North. To Math, the son of Mathonwy, went Gwydion. "Lord," said Gwydion, "I have heard that there have come into the South some animals such as were never known in this island before." "What are they called?" "Pigs, Lord." "And what kind of animals are they?" "They are small animals, and their flesh is better than the flesh of oxen." "Who owneth them?" "Pryderi,
But it was not so much to obtain the swine from Pwyll's son as to do a wrong to Math, the son of Mathonwy, that Gwydion offered to go to where Pryderi had his court. For Gwydion's brother had fallen deeply in love with a maiden who was close to Math, and the only way he might obtain her was by bringing Math, the son of Mathonwy, into war. For it was this way with Math, the son of Mathonwy: he could not exist unless his feet were in the lap of a maiden. Only when he was engaged in war could he separate himself from the maiden foot-holder. Now Goewin was the maiden who was with him at this time, and she was the fairest maiden who was known in Arvon. Gilvaethwy, the son of Math's sister and the brother of Gwydion, set his affections upon Goewin, and loved her so that he knew not what he should do because of her, and therefore, behold! his hue, and his aspect, and his spirits changed for love of her, so that it was not easy to know him. One day his brother Gwydion gazed steadfastly upon him. "Youth," he said, "what aileth thee?" "Why," replied Gilvaethwy, "what seest thou in me?" "I see," said his brother, "that thou hast lost thine aspect and thy hue; what, therefore, aileth thee?" "My lord brother," answered Gilvaethwy, "that which aileth me, it will not profit me that I should show to any." "What may it be, my soul?" "Thou knowst that Math, the son of Mathonwy, hath this property, that if men whisper together in a tone how low soever, if the wind meet it, it becomes known to him." "Yes," said Gwydion. "Now hold thy peace. I know thine intent." Then Gilvaethwy, when he found that his brother knew his intent, gave the heaviest sigh in the world. "Be silent, and sigh not," said Gwydion to him. "It is not thereby that thou wilt succeed. I will cause a war," he said, "that will separate Math, the son of Mathonwy, from his maiden foot-holder." It was then that Gwydion went before So Gwydion betook him to the magic arts that he knew, and he began to work a charm. And he caused twelve steeds to appear, and twelve black greyhounds, each of them white-breasted, and having upon them twelve collars and twelve leashes, such as no one who saw them could believe to be other than gold. And upon the steeds were twelve saddles, and every part which should have been of metal was entirely of gold, and the bridles were of the same workmanship. Then, with the steeds and the hounds, Gwydion appeared before Pryderi. "Lord," said he, "behold! here is a release for thee from the word thou spakest last night concerning the swine that thou couldst neither give them nor sell them. Thou mayst exchange them for that which is better. And I will give thee these twelve horses, all caparisoned as they are, with their saddles and their bridles, and these twelve greyhounds, with their collars and their leashes as thou seest." Then Pryderi and his council agreed to take the steeds and hounds, and let