[2][3] He was in the service of the King Louis XVI of France, as an officer in the Swiss Guards of his Maison Militaire du Roi (Royal Military Household).
[2] De Roll held the rank of lieutenant-colonel and was adjutant to the future Charles X of France (then the Count of Artois), the younger brother of the king who served as colonel of the Swiss Guards.
[3] Following the start of the French Revolution de Roll left France with Charles to join the Army of Condé, he thus avoided the massacre of his regiment in the Defence of the Tuileries by Republican forces on 10 August 1792.
[4][3] De Roll fought alongside Charles and the Army of Condé in the campaigns of 1792 and 1793 of the War of the First Coalition and was promoted to colonel.
[5] De Roll had requested that the British Army release all Swiss prisoners of war to him for incorporation into the regiment but this was not authorised and instead he recruited most of the men by traditional means in Switzerland, Alsace and Germany.