In 1740 the Prussian Army conquered Bohemian Silesia in the Silesian Wars and forced Maria Theresa in 1742 to cede the majority of Silesia, except the southernmost area with the duchies of Cieszyn, Krnov and Opava, to Prussia. In 1756 Prussian King Frederick II faced an enemy coalition led by Austria, when Maria Theresa was preparing for war with Prussia to reclaim Silesia. The Prussian army conquered Saxony and in 1757 invaded Bohemia. In the Battle of Prague (1757) they defeated the Habsburgs and subsequently occupied Prague. More than one quarter of Prague was destroyed and the St. Vitus Cathedral suffered heavy damage. In the Battle of Kolín, however, Frederick lost and had to vacate Prague and retreat from Bohemia.