A Collection of Folk Tales - One.

The Lady of the Lake & the Physicians of Myddfai

In the 12th century a young man fell in love with a woman who emerged from the magic lake – Llyn y Fan Fach, in the hills above the village of Myddfai. He was allowed to marry her providing he was faithful, didn't give her three needless blows, nor touch her with iron.
She came with a dowry of goats, cattle, sheep and horses. They were very happy and she bore him three sons.

Unfortunately, he struck his wife once when she laughed during a funeral, once when she cried at a wedding, and  accidently touched her with the metal bit of a bridle as she helped him to harness a horse.

She cried,“You have struck me the last blow. Farewell!” Turning her back on him, she called to the animals to follow her, and disappeared into the lake. The distraught husband drowned in the deep waters of the lake in his frantic search for her.

The lady’s three sons often went to the lake, and one day she re-emerged and told Rhiwallon, the eldest, that he must become a man of medicine and be "a benefactor to mankind by giving relief from pain and misery through healing all manner of diseases".

Rhiwallon and his sons Cadwgan, Gruffydd and Einion all became physicians. Their fame spread. They compiled a treatise published in The Red Book of Hergest, containing prescriptions such as this cure for coughs:-

Coarsely powdered mustard seed boiled with figs in strong ale – also for rheumatism, chilblains, and for preventing drunkenness.

The story of Lady of the Lake is a common old Welsh folk tale and it could possibly relate right back to early race memories of meetings between the two cultures, Celts and the people of the Bronze Age.
In some versions Rhiwallon is described as tall and fair and the lady as small and dark , typical attributes of both races.
Bronze Age people often lived on or beside lakes and were noted for their healing powers and understanding of herbal remedies etc. The warlike Celts arrived with the ability to forge iron. Their iron weapons would have struck fear into the hearts of the indigenous people – thus being ‘touched’ with iron could mean death.

An interesting source on Welsh folklore can be found here (BBC Myths and Legends)

Post information taken from here.