Osprey's study of one of the bloodiest conflicts of the Seven Years' War (1756-1763). In January 1758 Count Wilhelm Fermor marched into East Prussia at the head of 45,000 Russians. Frederick the Great was dismissive of the Russian army and failed to take the threat seriously. With the Russians laying siege to the fortress of Cüstrin, Frederick crossed the River Oder and cut their supply lines. On 25 August the two armies met at Zorndorf. This book details the bitter day-long battle in which the Russian infantry refused to buckle. Casualties were horrific, the Russians losing almost half their army. Frederick had managed to stave off the Russian threat but his opinion of their army had changed dramatically.