In the time of the Crusades, Elynas, the King of Albany (an old name for Scotland orAlba), went hunting one day and came across a beautiful lady in the forest. She was Pressyne, mother of Melusine. It is not clear whether he knew that she was of faierie blood. He persuaded her to marry him and she agreed, only on the promise that he must not enter her chamber when she birthed or bathed her children. Pressyne gave birth to triplet daughters. When he violated this taboo, Pressyne left the kingdom, together with her three children—Melusine, Melior, and Palatyne— and traveled to the lost Isle of Avalon.
The three girls grew up in Avalon. On their fifteenth birthday, Melusine, the eldest, inquired as to why they had been brought to Avalon. Upon hearing of their father’s broken promise, Melusine sought revenge. She and her sisters captured Elynas and locked him, with his riches, in a mountain. Pressyne became enraged when she learned what the girls had done, and punished them for their dishonor to their father. Melusine was condemned to take the form of a serpent from the waist down every Saturday. In other stories, she takes on the form of a mermaid.
Raymond of Poitou came across Melusine in a forest of Coulombiers in Poitou in France, and proposed marriage. Just as her mother had done, she laid a condition: that he must never enter her chamber on a Saturday. He broke the promise and saw her in the form of a part-woman, part-serpent, but she forgave him. When, during a disagreement, he called her a “serpent” in front of his court, she assumed the form of a dragon, provided him with two magic rings, and flew off, never to return.