House of Lusignan
According to European folklore the House of Lusignan was founded by the faerie Melusine. In the legend Melusine was exiled from Avalon and doomed to turn into a serpent from the waist down every Saturday. One day a prince, Raymondin of Poitou, came across her in the woods. He had just killed his uncle in a hunting accident and was distraught. Melusine helped him with this, and he later returned seeking her out. He proposed marriage, and she agreed on the condition that she be left alone every Saturday.