In my other life (where I'm Kari Maund) I'm a historian specialising in the Celtic-speaking countries, especially Wales. I've taught in several different British universities and published six books and a number of articles from 1987 onwards on everything from a mysterious murder in early eleventh century Wales to how many kings there were in ninth century Denmark (more than you'd think). Most of the articles are in academic journals and written for a university audience. (But if anyone wants details, I will happily supply them). The first three books were written for the same audience - one of them is the book of my PhD dissertation, one is a reference book and the third is an edited volume of papers about various elements of the reign of the Welsh king Gruffudd ap Cynan (1075-1137).
I've also written three books aimed at a more general audience.
The Welsh Kings (Tempus Books, Stroud 2000) is a history of the independent kingdoms that made up Wales and their various kings and princes from the end of the Roman Empire in Britain down to the conquest of Wales in 1283. It was written both for students and for anyone interested in Welsh history and is designed to provide a detailed overview.
The Four Musketeers: the true story of d'Artagnan, Porthos, Aramis and Athos (Tempus Books, Stroud 2005) This book began a long time ago in a conversation I had as a post-graduate student with my PhD adviser. The book came out of my love of the novels of Alexandre Dumas - especially the musketeer books. It's about the history of the musketeers, of the time in which they lived and of development of their legend. It's co-written with my partner, Phil Nanson, who is a military historian and we had a lot of fun writing it, including a research and photography trip to Gascony, where all four of the real musketeers were born. It's my favourite of my non-fiction.
Princess Nest: Seductress of the English (Tempus Books, Stroud 2007) Nest was the daughter of Gruffudd ap Rhys, prince of Deheubarth (South Wales) in the first part of the twelfth century, and she is known in Welsh legend as "the Helen of Wales". This book is both a biography of her - she was a strong character who lived in a very exciting time - and a study of what life was like for women in mediaeval Wales.
I'm happy to discuss Celtic, Gaelic, Anglo-Saxon and Viking history, but I can't do your homework for you, read your Celtic fantasy and critique it for accuracy, or conduct a detailed study into your ancestry. I'll happily offer suggestions on where you can start, but that's all. It sounds harsh, but it's simply an issue of time.