Need Help - Can't remember the title of a book!!! Updated

***Many thanks to pattepoilue - you're a genius! The Princes of Ireland: The Dublin Saga by Edward Rutherfurd is it!!! This has been driving me crazy for weeks -thank you, thank you, thank you!!!

I have been trying to remember the name of a rather long book I read a few years back and haven't been able to remember. I tried calling the library to see if they kept the titles you check out but they don't. I've tried putting keywords in google but I'm not having any luck.

Okay, I read this book about 5 years ago, and I don't think it was new even then. It was not a romance. It was a fictional story, but sort of a history of Ireland, from pre-celt to ?maybe early 20th century? (I'm not sure it even got that far). It started out with the pre-celts painting themselves before battle. There were several storylines as time moved forward, but I think they all were somehow related by a human skull used as a drinking cup that was passed from generation to generation. I think there was a forced marriage in the beginning of the book. It touched on when St. Patrick came to the island, there was a bit about a priest who made copies of the bible, I think he may have also had the Book of Kells. There were stories involving women, but they're very vague in my mind... The arrival of the Vikings were covered, and also the beginnings of the history of strife between the Protestants and Catholics.

It was as very thick book, and an interesting read, but it went slowly; it took me longer to finish this book than any other book I have read. For some strange reason I remember the cover being green.

Does this book ring any bells for anyone????