In December 1793, the French drove the soldiers of Habsburg Austria and Prussia from French soil in the Second Battle of Wissembourg and took positions beyond the eastern frontier. That spring the "Army of the Moselle" sent heavy reinforcements to northeast France, leaving the Rhine front lightly defended by troops under Jean René Moreaux. Taking advantage of French weakness, the main Prussian assault was aimed at Ambert who could only try to save as many of his troops as possible. Also on 23 May an Austro-Prussian army attacked the "Army of the Rhine" under Claude Ignace François Michaud but was repulsed at the Battle of Schifferstadt. After losing Kaiserslautern, the two French armies withdrew to positions closer to the frontier. Having expended almost the only initiative they displayed in 1794, the Prussians allowed their offensive to sputter to a halt.