Russian Pyotr Fyodorovich orig. Karl Peter Ulrich, duke von Holstein-Gottorp born Feb. 21, 1728, Kiel, Holstein-Gottorp died July 18, 1762, Ropsha, near St. Petersburg, Russia Tsar of Russia (1762). Grandson of Peter I, the young duke was brought to Russia by his aunt Elizabeth when she became empress (1741). Proclaimed the heir to the Russian throne, he was unpopular at court for his pro-Prussian attitude. After he succeeded Elizabeth (1762), he reversed her foreign policy, making peace with Prussia and withdrawing from the Seven Years' War. He offended the Orthodox church by trying to force it to adopt Lutheran practices. After six months he was forced to abdicate by a group of nobles, in collusion with his own wife, Catherine (later Catherine II), and Count Grigory Orlov, and was murdered while in the conspirators' custody