An A-Z of the Pagan Gods and Goddesses worshipped in Ancient Britain (there is more to the title but this is enough to get the idea) is a reference book, as you have probably guessed from the name.
I usually approach books like this with trepidation. I’m never sure what I’ll find in them. This book doesn’t just reference the Celtic Deities but rather all the deities worshipped in Ancient Britain.
At the very beginning of the book the authors explain why they chose these specific deities and what sources they used as their evidence. They give a short history and a timeline for the literary sources, which appears accurate.
Then comes the pages and pages of gods and goddesses. I’m not an expert on any of the gods but the information provided on the gods in the book can easily be checked by a little research.
I chose two gods that I do know a bit about to check the validity of their information. On the page about The Morrígan, they make a few connections that I have not seen anywhere else but on the whole I’d say 85% of what is on that page was good information. On the page about Lugh, I’d say 95% of the information provided is correct.
My prognosis: It is a good reference book to have with the caveat that you verify the information provided against other sources.