Grand Duchess Elena Vladimirovna of Russia (29 January 1882 – 13 March 1957), sometimes known as Helen, Helena, Helene, Ellen, Yelena, Hélène, or Eleni, was the only daughter and youngest child of Grand Duke Vladimir Alexandrovich of Russia and Duchess Marie of Mecklenburg-Schwerin. Her husband was Prince Nicholas of Greece and Denmark and they were both first cousins of... Wikipedia