After Peter succeeded to the Russian throne, he withdrew Russian forces from the Seven Years' War and concluded a peace treaty with Prussia. He gave up Russian conquests in Prussia and offered 12,000 troops to make an alliance with Frederick II of Prussia. Russia thus switched from an enemy of Prussia to an ally—Russian troops withdrew from Berlin and marched against the Austrians. The German-born Peter could hardly speak Russian and pursued a strongly pro-Prussian policy, which made him an unpopular leader. He was deposed by troops loyal to his wife, Catherine, the former Princess Sophie of Anhalt-Zerbst who, despite her own German origins, was a Russian nationalist. She succeeded him as Empress Catherine II. Peter died in captivity soon after his overthrow, perhaps with Catherine's approval as part of the coup conspiracy.