Having taken power in France during the 18 Brumaire on 9 November 1799, Napoleon was determined to return to Italy to reinforce the French troops in the country and retake the territory seized by the Austrians in the preceding years. In the spring of 1800 he led the Reserve Army across the Alps through the Great St Bernard Pass. The Austrian forces, under Michael von Melas, were laying siege to Masséna in Genoa and Napoleon hoped to gain the element of surprise by taking the trans-Alpine route. By the time Napoleon's troops arrived, Genoa had fallen; but he pushed ahead, hoping to engage the Austrians before they could regroup. The Reserve Army fought a battle at Montebello on 9 June before eventually securing a decisive victory at the Battle of Marengo.