While nearly every educated person has heard of the Battle of Hastings, not as many know that it was the third of three decisive battles fought in a period of four weeks:; the others were Gate Fulford and Stamford Bridge. Had things gone differently, Hastings could have been fought between Harald of Norway and William the Conqueror. At any rate, this page has some good background and campaign notes for this critical period.
And now for the ultimate reference site on the Roman Army: Red Rampant. This has got wonderful illustrations for just about everything you can think of relating to the Roman army and its enemies. It’s like an Osprey book, only much, much cheaper.
From a wargamer’s perspective, what’s not to like about the world’s greatest conqueror? Here’s a website on Genghis Khan with some good background information, including maps, biographical basics, and a nice look at Mongolia today. This last would be good for some of you doing the “Back of Beyond” games.
Rules writers pay attention! Mike Willegal has written an analysis of the effectiveness of black powder muskets.
Andy Watkins has this page with an amazing list of his ratings on hundreds of historical reference books. It’s worth checking before you take the plunge on a particular volume.