Osprey’s study of the campaign at Marengo in 1800 during the Napoleonic Wars (1799-1815). Having returned from Egypt and seized power as First Consul, Napoleon led the Army of the Reserve against the Austrian Army besieging Genoa. After a period of skirmishing and manoeuvring, Melas, the Austrian commander, launched a surprise attack on the morning of 14 June. The attack initially drove the French back to Marengo village and, despite committing the Consular Guard, by 3pm the French were retreating. Believing he had won, the wounded Melas left the field to his Chief-of-Staff, Zach. The timely arrival of Desaix’s Division led by Kellerman’s cavalry and the 9e Légère threw the Austrians into confusion, turned the battle in Napoleon’s favour, thus securing his position as First Consul. It could have been very different.