Bloody affair at PraguePrague, Czechia
After Frederick had forced the surrender of Saxony in the 1756 campaign, he spent the winter devising new plans for a defence of his small kingdom. It was not in his nature, nor in his military strategy, simply to sit back and defend. He began drawing up plans for another bold stroke against Austria.
In early spring the Prussian army marched in four columns over the mountain passes separating Saxony and Silesia from Bohemia. The four corps would unite at the Bohemian capital of Prague. Though risky, because it exposed the Prussian army to a defeat in detail, the plan succeeded. After Frederick's corps united with a corps under Prince Moritz, and General Bevern joined up with Schwerin, both armies converged near Prague.
Meanwhile, the Austrians had not been idle. Though initially surprised by the early Prussian attack, the able Austrian Field Marshal Maximilian Ulysses Count Browne had been retreating skillfully and concentrating his armed forces towards Prague. Here he established a fortified position to the east of the town, and an additional army under Prince Charles of Lorraine arrived swelling the Austrian numbers to 60,000. The prince now took command.
Frederick the Great's 64,000 Prussians forced 61,000 Austrians to retreat. The Prussian victory was at a high cost; Frederick lost over 14,000 men. Prince Charles had also suffered heavily, losing 8,900 men killed or wounded and 4,500 prisoners. Given the high casualties he had suffered, Frederick decided to lay siege rather than launch a direct assault on the walls of Prague.