Every Celtic name carries a story; Danu carries more than one.
The story
Danu is an earth goddess, mother of the Tuatha Dé Danann, and a goddess of fertility, wisdom, and wind. She is often depicted as a nurturing figure, and is associated with symbols like crowns and keys. The Tuatha Dé Danann are the Irish gods who may be considered to be extensions of Danu, or as distinct individuals.
Other Celtic figures on The Veiled Deck: Cernunnos, Chailleach, Dagda.