Fairy faith
The belief in an otherworld people living beside humans, held in Ireland, Scotland, Wales and Brittany and treated with courtesy and caution.
Also: good people, sídhe, aos sí, tylwyth teg, the fair folk
The fairy faith is the Celtic-language world's belief in an unseen people, called the Good People, the Gentry, the aos sí in Irish, the Tylwyth Teg in Welsh. They are said to live in hills, mounds and forts, and to take offence when land is disturbed. Customs protect against them: not naming them directly, leaving a thorn tree or a ring-fort alone, keeping iron near a baby. Walter Evans-Wentz gathered testimony in The Fairy-Faith in Celtic Countries in 1911. Folklorists treat it as a way of explaining illness, the dead and the land, and some interviewees still say they would not cut a certain bush. Related beliefs appear in Scandinavia and the Slavic lands.