During the War of the First Coalition against the First French Republic, he directed the sieges of Fort-Louis in 1793 and Mannheim in 1795. In 1796, he was named chief of staff of the army sent to oppose Napoleon Bonaparte in Italy, fighting at Bassano and Mantua. In 1800, he was appointed deputy commander of the main army in southern Germany, which ended in disastrous defeat at Hohenlinden in December. He was made the scapegoat for this failure and dismissed from the service shortly thereafter.