By early September, Archduke Charles defeated Jourdan’s army at Amberg and Würzburg and the French had retreated northwest across the foothills of the Vogelsberg mountains, reaching the Lahn on 9 September. Jourdan arrived with 25,000 infantry, 5,000 cavalry, and about 6 artillery batteries. There Jourdan's army was joined by 16,000 fresh troops commanded by General François Séverin Marceau-Desgraviers (Marceau), who had abandoned his blockade of Mainz. With his now superior numbers, Jourdan decided to defend the line of the Lahn in the hope that he could keep the Archduke's army occupied, and prevent him from turning south to attack Jean Victor Moreau's army in the Black Forest. With some kind of luck, he himself might be able to slip away to the south and join with Moreau as he defiled from the Black Forest.