The first tale in Tales of the Basque Country is called La dame d'Anboto. Don Diego López de Haro was a hunter who lived in Bizkaia. One day, while he was hunting, he heard a wondrous chant. He soon found who was singing: it was a woman of astonishing beauty. She was “tall, ellegant, she had very white skin, dark and profond eyes, blond hair. She wore a green dress with gold.”
Diego fell in love with the woman and asked her to marry him. She agreed, as long as he never said the word “God”.
The got married and had a daughter and a son, Íñigo. One day, accidentally, Diego let out the word “God”. Mari took her daughter with her and dissapeared.
Some years later, Diego had to fight in Spain and he was emprisoned in Toledo. Íñigo went to look for his mother to ask her for help. He found her on a tree. She gives him a white horse, who helps him rescue his father. After that, father and son lived in the castle, and every day they made and offer to Mari, the Lady of Amboto.
This legend reminds me a bit of La corza blanca(The white doe) by Bécquer. It is set in the North of Aragón, which is quite close to Bizkaia. The hero of this story is Garcés, a hunter who is in love with Constanza. Constanza is very similar to the lady of Amboto: she is pale and blonde as gold, with eyes as dark as night.
When he is hunting, Garcés hears a beautiful chant, that seems to be coming from a group of does. He gets ready to kill them, but then they dissapear and a group of women appears instead. Between them, he recognizes Constanza.
He convinces himself that it was just a dream. The next time he sees the doe, he kills it, only to find Constanza dead.
Speaking of white does, Snape’s Patronum in Harry Potter was also a white doe. It was Lily. Snape loved Lily. He killed her. IT IS ALL CONNECTED!