Prussian lands outside the Empire. The centuries-long rise of the Austrian House of Habsburg had already begun with King Rudolph's victory at the 1278 Battle on the Marchfeld and the final obtainment of the Imperial crown by Emperor Frederick III in 1452. His descendants Maximilian I and Philip the Fair by marriage gained the inheritance of the Burgundian dukes and the Spanish Crown of Castile (tu felix Austria nube), and under Emperor Charles V, the Habsburg realm evolved to a European great power. In 1526 his brother Ferdinand I inherited the Lands of the Bohemian Crown as well as the Kingdom of Hungary outside the borders of the Empire, laying the foundation of the Central European Habsburg monarchy. From the 15th to the 18th century, all Holy Roman Emperors were Austrian archdukes of the Habsburg dynasty, who also held the Bohemian and Hungarian royal dignity. After the Protestant Reformation, the Catholic Habsburgs had to accept the 1555 Peace of Augsburg and failed to strengthen their Imperial authority in the disastrous Thirty Years' War. Upon the 1648 Peace of Westphalia, Austria had to deal with the rising Brandenburg-Prussian power in the north, that replaced the Electorate of Saxony as the leading Protestant estate. The efforts made by the "Great Elector" and the "Soldier-king" Frederick William I had created a progressive state with a highly effective Prussian Army that, sooner or later, had to collide with the Habsburg claims to power. History The rivalry is largely held to have begun when upon the death of the Habsburg Emperor Charles VI in 1740, King Frederick the Great of Prussia launched an invasion of Austrian-controlled Silesia, starting the First Silesian War (of three Silesian Wars to come) against Maria Theresa. Frederick had broken his promise to acknowledge the Pragmatic Sanction of 1713 and the indivisibility of the Habsburg territories, whereby he sparked off the pan–European War of the Austrian Succession. He decisively defeated the Austrian troops at the 1742 Battle of Chotusitz, whereafter Maria Theresa, by the Treaties of Breslau and Berlin, had to cede the bulk of the Silesian lands to Prussia. At the time, Austria still claimed the mantle of the Empire and was the chief force of the disunited German states. Until 1745, Maria Theresa was able to regain the Imperial crown from her Wittelsbach rival Charles VII by occupying his Bavarian lands, but, despite her Quadruple Alliance with Great Britain,