 Complete the following phrase:  Prince and Princess Cantacuzène resided in St. Petersburg later Petrograd or at their estate in Ukraine during their early married years, with the Princess giving birth to their three children, Mikhail Mikhailovich, Barbara or Bertha Mikhailovna, and Zinaida Mikhailovna. Princess Cantacuzène remained in St. Petersburg during World War I in which Prince Cantacuzène served as aide-de-camp and later Major-General, and finally General, in the service of Tsar Nicholas II. He served with distinction and was wounded in battle in 1914; as commander of the South Russia Cossacks, in 1915 he led 15,000 men in what has been called the last great cavalry charge against a fortified position in military history. The family left Russia in the aftermath of the 