A battle between the Prussian army, led by Prince Hohenlohe, and Napoleon’s French forces, fought near the German town of that name. The Prussians underestimated the size of the French force and were comprehensively defeated. The defeat by Davout of the Duke of Brunswick’s main Prussian army at Auerstädt on the same day left the road to Berlin unprotected. After its double defeat Prussia embarked on a series of military, political, and social reforms in order to be able to challenge the French.