Morgan le Fay, alternatively known as Morgan[n]a, Morgain[a/e], Morgant[e], Morg[a]ne, Morgayn[e], Morgein[e], and Morgue[in] among other names and spellings, is a powerful and ambiguous enchantress from the legend of King Arthur, in which most often she and he are siblings. According to the different authors, she is a fairy or a human; beneficial or harmful; either a sister, half-sister, or unrelated to Arthur. A significant aspect in many of Morgan's medieval and later iterations is the unpredictable duality of her nature, with potential for both good and evil.