The sudden death of Empress Elizabeth of Russia in January 1762 led to the succession of the Prussophile Peter III, her German nephew (simultaneously Duke of Holstein-Gottorp). This "Miracle of the House of Brandenburg" led to the collapse of the anti-Prussian coalition; Peter immediately promised to end the Russian occupation of East Prussia and Pomerania, returning them to Frederick. One of Peter III's first diplomatic endeavors was to seek a Prussian title from Frederick, which Frederick naturally obliged. Peter III was so enamored of Frederick that he not only offered him the full use of a Russian corps for the remainder of the war against Austria, he also wrote to Frederick that he would rather have been a general in the Prussian army than Tsar of Russia. More significantly, Russia's about-face from an enemy of Prussia to its patron rattled the leadership of Sweden, who hastily made peace with Frederick as well. With the threat to his eastern borders over, and France also seeking peace after its defeats by Britain, Frederick was able to fight the Austrians to a stalemate and finally brought them to the peace table. While the ensuing Treaty of Hubertusburg simply returned the European borders to what they had been before the Seven Years' War, Frederick's ability to retain Silesia in spite of the odds earned Prussia admiration throughout the German-speaking territories. A year following the Treaty of Hubertusberg, Catherine the Great, Peter III's widow and usurper, signed an eight-year alliance with Prussia, albeit with Russian favoured conditions.