Of all the folk fairy tales of Wales, that of the Lake Maidens who married mortals has had the widest distribution and the longest life. There are many sinister fairies in Welsh tradition, but the Welsh water-fairies are not among them. They are beautiful and desirable, but they are not sirens or, nixies. John Rhys devotes a chapter in Celtic Folk-Lore (Chapter I) to 'Undine's Kymric Sisters'.

The best-known and the earliest of the stories about the Gwragen Annwn is the story of the lady of Llyn y Fan Fach, a small and beautiful lake near the Black Mountains.

It happened in the 12th century that a widow with a farm at Blaensawde, near Mydfai, used to send her only son two miles up the valley to graze their cattle on the shores of Llyn y Fan Fach. One day, as he was eating his midday snack, he saw the most beautiful lady he had ever seen, sitting on the surface of the lake combing the curls of her long golden hair with the smooth water as her mirror. He was at once fathoms deep in love, and held out his hands with the bread in them, beseeching her to come to shore. She looked kindly at him, but said, 'Your bread is baked too hard' and plunged into the lake.

He went back and told his mother what had happened. She sympathized with him and gave him some unbaked dough to take next day. That was too soft, so the next day his mother gave him lightly baked bread. That passed the test, for three figures rose from the lake: an old man of noble and stately bearing with a beautiful daughter on each side of him. The old man spoke to the farmer saying that he was willing to part with his daughter if the young man could point out to him the one on whom his love was set. The fairy ladies were as like as two peas, and the farmer would have given it up in despair if one of them had not slightly moved her foot so that he recognized the distinctive lacing of her sandal and made the right choice. The fairy father gave her a dowry of as many cattle as she could count in a breath — and she counted quickly — but warned her future husband that he must treat her kindly, and if he gave her three causeless blows she and her dowry would be lost to him for ever.

They married and were very happy, and had three beautiful boys, but she had strange, fairy-like ways; she fell sometimes into a kind of trance, she was apt to weep when other people rejoiced, as at weddings, and to laugh and sing when other people were mourning, as at a child-funeral, and these peculiarities were the cause of his giving her three causeless blows, mere love-taps but a breach of the taboo, so that she was forced to leave him, taking with her all her cattle and their descendants, even to the slaughtered calf hanging against the wall.

She did not forget her three sons, however, for she visited them and taught them deep secrets of medicine so that they became the famous physicians of Mydfai, and the skill descended in their family until it died out in the 19th century.

This tale Rhys reproduced from The Physicians of Mydfai by Rees of Tonn, but he also recorded variations of it from oral collections, adding fresh details in some versions, though some were rudimentary. Wirt Sikes in British Goblins tells the same story in considerable detail, but without giving his source, as Rhys is careful to do. In all the stories the taboo is, in the end, violated and the fairy disappears, just as the wedded seal maidens regain their skins and return to their element.

[Motifs: F241.2; F300; F302.2]