In Celtic folklore, the Irish: leannán sí "Barrow-Lover", Scottish Gaelic: leannan sìth; Manx: lhiannan shee is a beautiful woman of the Aos Sí (people of the barrow or the fairy folk) who takes a human lover. Lovers of the leannán sídhe are said to live brief, though highly inspired, lives. The name comes from the Gaelic words for a sweetheart, lover, or concubine and the term for a barrow or fairy-mound.
The leannán sídhe is generally depicted as a beautiful muse, who offers inspiration to an artist in exchange for their love and devotion; however, this frequently results in madness for the artist, as well as premature death. W. B. Yeats popularized a slightly different perspective on these spirits with emphasis on their vampiric tendencies.
The Leanhaun Shee (fairy mistress) seeks the love of mortals. If they refuse, she must be their slave; if they consent, they are hers, and can only escape by finding another to take their place. The fairy lives on their life, and they waste away. Death is no escape from her. She is the Gaelic muse, for she gives inspiration to those she persecutes. The Gaelic poets die young, for she is restless, and will not let them remain long on earth—this malignant phantom.
One can find more information about leannán sídhe in older texts and folk lore. Though they are not called leannán sídhe directly, they fit the descriptions to be a 'leannán sídhe. Books to look into, with the specific stories to read are: Katherine Briggs' "The Fairy Follower" in Folktales of England; the story "Oisin in the Land of Youth" in Ancient Irish Tales; "The Dream of Angus" in Lady Gregory's Cuchulain of Muirthemne; and the poem called "Fuadach/ Abduction" by Nuala Ní Dhomhnaill.
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