In Celtic* mythology, Danu (also known as Dana, Anu, and Don) is a fertility goddess and mother of the Tuatha Dé Danaan, a group of Irish gods. The worship of Danu originated in eastern Europe, and because she was associated with rivers, many European rivers carry versions of her name, including the Danube, the Don, and the Dnieper.
deity god or goddess
Some scholars believe that the Tuatha Dé Danaan were gods of the people who inhabited Ireland before the Celts. When these deities were defeated by another group, the Sons of Mil, they went to live underground. Each god received a personal domain, and the group eventually became known as "the little people" of Irish fairy stories.
See also Celtic Mythology.