I've picked up Goodrich's King Arthur to do some research, but I have to admit that my only basis for doing so was a google search for "definitive works on historical King Arthur." It was also published in '89.
Is Goodrich still seen as a laudable source, academically? If not, then who is? Is there anywhere I can go (besides paying to go to a university) to get a barometer reading for what scholars currently consider good material and dominant theories on this sort of thing?
I'm also interested in any supplementary material on sub-Roman Britain, the character of Merlin, and the interaction between Ireland and Britain during the time they are purported to have lived.
Thanks in advance!
There was one written very recently in fact, by noted early medieval historian Guy Halsall, called Worlds of Arthur.
It is probably one of the best and most accessible histories out there of dark age england, if not for any other reason than he is able to efficiently and ruthlessly quash the rampant speculation and frankly outright imaginative fabrications of many popular pseudo-historians.
A great book for a breakdown of the era and the mythology of the "historical" king arthur. Less so for someone looking to have their fantasies stroked.
If you want to not pay for the book, I can sum up his thesis as "there is nothing meaningful we can say about a historical King Arthur, because a critical reading of the available history can't even verify his existence on the most cursory of levels."
But this is of course, for history, and not mythology. There is a lot of good work being done on the mythology, but this is unfortunately out of my realm of knowledge.
Many universities and societies in both the UK and US host research seminars or conferences on where Arthurian romance might come up. These may be intermittent/hard to come by, and conferences will usually have a fee (research seminars are usually free), but you will be at the cutting edge of research. I am afraid my interests in Arthur are not related to a historical figure but what the romances tell us about the contemporary (to when they were told/recorded) societies. If you do have a particular interest in that regard do let me know.