[1] After a short imprisonment on a charge of inciting riots in Haguenau, Westermann moved to Paris in May 1792, where he became an ally of revolutionary leader Georges Danton.

[1] Westermann played an leading role in the overthrow of the French monarchy on 10 August 1792, where he commanded a unit of fédérés in the attack on the Tuileries Palace.

[1] Denounced by Jean-Paul Marat to the National Convention, Westermann succeeded in proving his innocence, and was sent with the rank of general of brigade to quell the Revolt in the Vendée.

[2] Appointed commander of the vanguard of the Army of the Coasts of La Rochelle on 18 May 1793, he defeated the rebels at Parthenay on 20 June, then captured Châtillon on 3 July.

[6] After his victory, in January 1794 Westermann was summoned to Paris, where, as a friend and partisan of Danton, he was proscribed and sentenced to death by the Revolutionary Tribunal.