Here’s another excellent, concise summary of an aspect of Irish mythology from Ruth at the Celtic Myth Podshow:
The Tuatha de Danann, the people of the Goddess Danu, were one of the great ancient tribes of Ireland. The important manuscript ‘The Annals of the Four Masters’, records that they ruled Ireland from 1897 B.C. to 1700 B.C.
The daoine sídhe or faeries of Ireland are said to be the descendants of this noble lineage.
In the world of Taylor Smart, the sídhe sometimes swear by saying “Danu!” or “By Danu!” I haven’t gone into any detail how contemporary sídhe remember and/or reverence their distinguished ancestors. Perhaps a bit of that will trickle into the third book of the Into the Wonder series, Oak, Ash, and Thorn.