Folio 309r of the Book of Kells (Trinity College Dublin), c. 800.
Key myth
The Tuatha Dé Danann are 'the peoples of the goddess Danu', but no myth about Danu survives. Cormac's Glossary mentions a goddess Anu, 'mother of the Irish gods'.
Where sources differ or caution applies. Almost nothing is recorded about her; the idea of a great Celtic Mother Goddess is largely a modern construct.