Chronofus has written a set of free miniature wargames rules called Piracy, and also an amazing amount of supplemental and source material on pirate captains, pirate history, pirate flags, nations of the Caribbean, slavery, clothing, weapons, currency, towns and more!
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.
Historical miniature gamers can never have enough research material. Here is a huge collection of primary source material on the United States from the Antebellum through Reconstruction. This University of Michigan digital library has 8,500 books and 50,000 journal articles with 19th century imprints. The collection should be of particular interest to Civil War and Mexican American war gamers.