A second book that has provided useful information regarding the Celts is The Celtic Realms. Written by Myles Dillion and Nora Chadwick, it is more like a survey of the Celts of the British Isles from their beginnings. It is an introduction to literature, religion, and visual arts of this ethic group. It was first published in 1967, but this cover is from the 2006 edition published by Castle Books.
1. Discovering The Celts
2. The History and Geography of The British Isles To The End of The Roman Period
3. The Celtic Revival
4. The Formation of The Historical Celtic Kingdoms
5. Secular Institutions: Early Irish Society
6. The Early History of The Modern Celtic Kingdoms
7. Celtic Religion and Mythology and The Literature of The Otherworld
8. Celtic Christianity and Its Literature
9. The Celtic Language and The Beginnings of Literature
10. Irish Literature
11. Welsh Literature
12. Celtic Art
A good read for those who like to go to the roots.