In 1367 Emperor Charles IV also purchased the former March of Lusatia (Lower Lusatia) in the northwest, however, during the Thirty Years' War both Lusatias passed to the Electorate of Saxony by the Peace of Prague. After the Bohemian Crown (Crown of Saint Wenceslas) passed to the House of Habsburg in 1526, the Bohemian crown lands together with the Kingdom of Hungary and the Austrian "hereditary lands" became part of the larger Habsburg Monarchy. In 1742 the Habsburg queen Maria Theresa lost the bulk of Silesia to Prussia upon the First Silesian War, part of the War of the Austrian Succession.