In the spring of 1792 he received the rank of marechal de camp in command of the cavalry in the army of the north; but the influence of the extremists becoming predominant he took indefinite leave of absence, and settled at Auteuil, where, with Condorcet and Cabanis, he devoted himself to scientific studies.
Santerre was appointed marechal de camp on the 23rd of October 1792, and subsequently general of division.
He served in the army as marechal-de-camp under Luckner and Lafayette, but was accused of treason on the 15th of August 17 9 2, fled the country, and was imprisoned by the Austrians.
Of his two brothers, Theodore Lameth (1756-1854) served in the American war, sat in the Legislative Assembly as deputy from the department of Jura, and became marechal-de-camp; and Charles Malo Francois Lameth (1757-1832), who also served in America, was deputy to the States General of 1789, but emigrated early in the Revolution, returned to France under the Consulate, and was appointed governor of Wiirzburg under the Empire.
Thanks to the friendly intervention of the marechal du camp, baron Duteil, Bonaparte once more gained leave of absence for three months and reached Corsica in September 1791.