 His father, Duke George, who was only the second son of the reigning Duke of Oldenburg, had no prospects of inherited his father's state or fortune of his own and was living in Russia since his marriage in 1809 to Grand Duchess Catherine Pavlovna of Russia.Duke George, who had been appointed governor on the Volga, died six month after Peter, his second, was born.Peter's mother Grand Duchess Catherine Pavlovna of Russia was the favorite sister of Tsar Alexander I of Russia who took his two nephews, Peter and his older brother Alexander, under his protection.