July, Michaud was ordered to move west to attack Trier near Luxembourg. In mid-September the Prussians attacked the weakened French forces in the north-eastern frontier and reoccupied Kaiserslautern. The French returned and the fighting continued until the Austrians abandoned the Netherlands and withdrew to the Rhine at Coblenz. With their northern flank now dangerously exposed, the coalition armies in the Upper Rhine withdrew east to the fortified city of Mainz. References Sources Further reading Battles of the French Revolutionary Wars Battles of the War of the First Coalition Battles involving Austria Battles involving France Battles involving Prussia Battles in Rhineland-Palatinate