Outlaws and Highwaymen is a terrific site loaded with information about English criminal history.a
Here are a set of useful pages with information on gaming the Reconquista.
The Conquest of Mexico is a period I’ve always wanted to game. Steve’s Balagan website has a very useful web page of information and links to resources on the Aztecs and other inhabitants of Mesoamerica.
For a terrific collection of color plates of French military costume from the Gauls to 1806, visit The New York Public Library digital galleries.
The New York Public Library Images collection has an amazing collection of the uniforms of Russian armed forces from 960 – 1900. Most are in color. All are useful.