In the Battle of Pirmasens on 14 September, Moreaux was defeated by a Prussian army under Charles William Ferdinand, Duke of Brunswick-Wolfenbüttel. The name of the French commander of the "Corps of the Vosges" is spelled "Moreau" in historian Digby Smith's account. Another authority, Ramsay Weston Phipps noted that Moreaux was often spelled "Moreau" and confused with the more famous Jean Victor Marie Moreau. In fact, Jean Victor Moreau was not promoted to general of division until 14 April 1794. Moreaux led 12,000 men to attack the Prussian camp at Pirmasens. The Prussians were on the alert and prepared to defend themselves in strong positions. The French generals expressed doubt about continuing, but the representatives on mission demanded an assault. Accordingly, the French attacked along three valleys and were repulsed by heavy flanking fire. The French lost 4,000 casualties and 22 guns. The Prussians reported only 167 casualties.