Villehardouin is a free map-and-counter board game from the great designers at Perfect Captain. It’s a game about the Byzantine Reconquest of the Morea in southern Greece in the year 1263 AD.
Medieval
Richard and Saladin: Warriors of the Third Crusade
The Shadowed Realm site has an article on Richard the Lionheart and Saladin, which provides good background for anyone thinking of starting a Crusades gaming project.
By The Walls of Constantinople One Page Board Game
By the Walls of Constantinople is a one-page board game simulating part of the seige of the city by the Sultan Mahmet II. To play the game, you just download one of the listed images and print.
BattleLore Historical Scenarios
BattleLore Master has a number of historical scenarios for the popular game, including Hastings, Lincoln, and Stirling Bridge.
Teutonic Order Banners
The Warfare East site has a jpg image of Teutonic Knight banners to download, print and cut out.