Grand Armee: Great Battles of the Napoleonic Wars Miniature Wargame Rules System

From the author's website:

Grande Armée is a set of rules by which players can use miniature figures of any size or basing system to recreate the famous, large-scale battles of the Napoleonic wars. In wargame parlance, it is "grand-tactical" in scope, in that players command entire armies, moving whole corps and divisions on the table. The basic unit on the table-top is the brigade, representing a few thousand soldiers. At this scale, of course, many things are abstracted. We do not concern ourselves with the actions of small groups of soldiers. Rather, we place ourselves in the roles of generals, ordering thousands of men to move, attack, or defend. And, like those generals of history, we don't know whether or not our officers and men are going to behave exactly as we hope or expect.