The book is a collection of Irish legends compiled by the renowned folklorist and linguist Jeremiah Curtin. Drawn from Gaelic storytellers, the author grouped these legends into two categories: the first offers Irish versions of common European fairy tales; the second contains stories from the Fenian cycle—about Finn MacCumhail and his warriors, the Fenians of Erin. In all the stories, fairy-tale elements are present, including battles with giants, the dead returning to life, people turned into animals, wondrous lands of eternal youth, and heroes with incredible strength.