I was poking around at some history for a vampire game I wanted to run set in the late 1700s, and I was curious where a 1000 year-old vampire would come from, so I did some study on the late 8th century,
and this page is the result.
It's chump-change stuff, as far as the more serious historians here are (almost all of it is just from Wikipedia), but you might find it useful.