On 14 June 1800 the village was the scene of an important battle between the French army commanded by Napoleon and an Austrian army led by Melas. Every second Sunday in June, there is traditionally a costumed commemoration of the battle, drawing many international visitors. According to local legend, Majno, a thief who was said to have robbed Pope Pius VII while on his way to Paris in 1804 to crown Napoleon emperor, laid up in hiding in the woods of Fraschetta, just by Spinetta Marengo.
The famous dish Chicken Marengo is named after the town. According to legend, Napoleon's chef created the dish from the few ingredients he could find after the battle, using a sabre instead of a cooking knife.
There is a museum, founded in 1846, containing weapons and relics of the battle.
The Marengo treasure
In 1928 precious objects from the Roman period were uncovered by farmers in a field near the village of Marengo. Dating from the 2nd century, the objects, all in very bad condition, included a silver bust representing the emperor Lucius Verus and a silver vase decorated with acanthus leaves. The objects today are conserved in the Museum of Antiquity of Turin, awaiting restoration.