On 4 March 1796, Charles Eugène was promoted to Lieutenant Field Marshal . In 1796 he served in Germany under Field Marshal Dagobert Sigmund von Wurmser in the Army of the Upper Rhine; on 11 May of that year, he was awarded the Commander's Cross of the Military Order of Maria Theresa Order. He fought with distinction at the Battle of Amberg on 24 August and in the Battle of Würzburg on 2 September, commanding a brigade of cavalry.