Each year on the First of August it is said a water faerie can be seen on the surface of Llyn y Fan Fach, a mountain lake in the Myddfai region of Wales.
She is perhaps the same faerie who, in the 12th Century married a local farmer named Gwyn. He tried to catch her attention by offering a gift of bread, but she refused as it was too hard. The next day she found his bread too soft. On the third day however she found the bread to her liking and accepted his offer of marriage.
Her father said he would allow his daughter to marry a mortal if young Gwyn could tell her apart from her identical twin. Gwyn has having difficulty distinguishing between the sisters, but at last one moved her foot slightly and he recognised his love.
As a wedding gift she brought from the lake many fairy cows, sheep and horses, and they all settled on Gwyn’s farm. There was one condition the faery placed upon their marriage however, that if Gwyn should strike her three times during their life together she would leave forever. But the years that followed were happy ones and the couple had three fine sons.
Then one day, Gwyn tapped his wife on the shoulder. At this she began to weep and said he had stuck the first blow. Later at a wedding she started to sob, but when Gwyn patted her shoulder to comfort her she said he had struck the second blow. From now on Gwyn took all care to do touch his wife in any way that could be considered a blow, until one day they attended a funeral. The Faery started laughing during its course and Gwyn, embarrassed, put his hand on her arm to quiet her. This was to be the final blow, and she left her broken-hearted husband and returned under the lake’s surface with her dowry of fairy animals.
The farmer never saw his wife again, although she would sometimes come to the surface to teach her eldest son the secrets of herbal medicine. He and his descendants became the famed Physicians of Myddfai. The last of the family line descended from the farmer and the lake faery died out in the 19th Century.