Austro-Prussian rivalry
It had extended most of its territory into the eastern Neumark region, and after the War of the Jülich succession by the 1614 Treaty of Xanten also gained the Duchy of Cleves as well as the counties of Mark and Ravensberg located in northwestern Germany.
In 1653, the "Great Elector" Frederick William acquired Farther Pomerania and reached full sovereignty in Ducal Prussia by the 1657 Treaty of Wehlau concluded with the Polish king John II Casimir Vasa.
[1] 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.
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.
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, the Dutch Republic and Saxony, she failed to recapture Silesia: The Second Silesian War started with Frederick's invasion into Bohemia in 1744 and after the Prussian victory at the 1745 Battle of Kesselsdorf, by the Treaty of Dresden the status quo ante bellum was confirmed: Frederick kept Silesia but finally acknowledged the accession of Maria Theresa's husband, Emperor Francis I.
Her capable state chancellor, Prince Wenzel Anton of Kaunitz, succeeded in the Diplomatic Revolution of 1756, allying with the former Habsburg nemesis France under King Louis XV in order to isolate Prussia.
Frederick, on the brink, was saved by the discord among the victors in the "Miracle of the House of Brandenburg", when Empress Elizabeth of Russia died on 5 January 1762 and her successor Peter III concluded peace with Prussia.
