She was an insignificant German princess from Stettin, the daughter of a impoverished duke: Sophie of Anhalt-Zerbst, known as Fieke. At just fourteen years old, she was sent to Russia to marry her cousin Peter of Holstein-Gottorp, who had been designated as her successor by his aunt, the Russian Empress Elizabeth. Sophie became Catherine. She converted to the Orthodox faith, learned Russian, and became interested in Russian culture and its traditions. She endured the horrors of a marriage to her unloved and sadistic husband. On December 25, 1761, he ascended the Russian throne as Tsar Peter III. Seven months later, he was dead, dethroned and murdered. At the age of thirty-three, Catherine ascended the throne and ruled as the sole sovereign over the vast Russian Empire for more than forty-seven years.