Here's a site that is just so spiffy for a history freak like myself: Early British Kingdoms. This site concerns itself with the little-known history of the indigenous Celtic population of Britain between the time of the withdrawal of the Romans (around 400, more or less) and the time of Anglo-Saxon domination of the island after about 650. In other words, the time period generally known as the early Dark Ages. It's comprehensive, extremely well-researched and organized, and a sure time-sink for me in the next few days (following our move, of course ...) It also includes an excellent section on historical Arthuriana.
Geneaological research has strongly suggested that at least one line of my descent comes down from the Welsh aristocracy and part of my enthusiasm for reading this kind of stuff is the possibility that I may be reading my own ancestors' histories. In any case, many of "my people" came from England, Wales and Scotland so some of my ancestors (at least) lived in this place, at this time. Perhaps my imagination is childishly overactive, but reading these histories I feel a real connection, as opposed to reading, say, Japanese history. Which is very interesting by itself, but I read with detachment because it is a culture whose connection to my own is very recent, very little understood and therefore too shallow for me to explore to greater depths. It's largely this greater-than-normal connection I feel with what I understand to be my ancestors that has meant that I embrace pagan religion.