The allies of Austria had formed the VIIth and VIIIth Federal Corps of the German Confederation. Both corps had advanced northward to support Hanover. When Hanover surprisingly surrendered the VIIth Corps, built by the Bavarians, stood in Thuringia. The VIIIth Corps, built by troops of Hesse, Baden and Wuerttemberg, stood north of Frankfurt. At first the Prussians attacked the VIIth Corps. The Bavarian troops lost combats at Hünfeld and Dermbach on 4 July and withdrew to the river Franconian Saale. But the Prussians followed quickly across the mountains of the Rhön and beat the Bavarians in the battle of Kissingen and Hammelburg on 10 July.