The 2nd Battalion also contributed to General Adam Philippe, Comte de Custine's Army of the Rhine "Armée du Rhin" and its conquest of the Palatinate and was garrisoned in Mainz after this successful campaign. After the Defence of the City later that year, the battalion remained in the city until the capitulation of the garrison the next year. The Prussians carelessly paroled the garrison on the promise not to fight against the Coalition armies for one year. It was noted that the terms did not prevent the troops from being used to fight the Vendeans, so the parolees were hurried west. These 14,000 well-disciplined soldiers became the unofficially named Army of Mayence under Jean-Baptiste du Bayet. They were soon fighting with the Army of the Coasts of Brest under Jean Baptiste Canclaux near Nantes.