Marengo is an operational level simulation of the battle between Napoleon's French Army and the Austrian Army commanded by General von Melas, which occurred on June 14, 1800 in Piedmont (northern Italy).
One of Napoleon's first important victories, the battle was decided by the opportune arrival of French reinforcements who robbed Melas of the triumph he had almost achieved earlier in the day. For the rest of his career, on many more famous battlefields, Napoleon often exhorted his troops with the mention of the glorious French victory of Marengo.
One on four games included in the Napoleon At War QuadriGame. The games in this set are based on the Napoleon At Waterloo system which is a basic "Movement-Combat" system with hard "Zones of Control". There are four pages of standard rules and one page of Exclusive rule.
(from the rules folder and BGG user)