The rise of Napoleon Bonaparte, whom he supported in the Coup of 18 Brumaire (November 1799), brought him further opportunities under the Consulate and Empire. In the campaign of 1800 he was chief of staff to Louis-Alexandre Berthier, the nominal commander of the Army of Peierve of the Ains which won the Battle of Marengo. After the battle he sustained a successful combat, against greatly superior forces, at Pozzolo.