 The couple married on 21 August 1911, in St. Petersburg, Russia.Helen studied medicine at the University of St. Petersburg following their marriage, a career pursuit she had to give up when she gave birth to her first child.The couple had two children, Prince Vsevelod Ivanovich of Russia (20 January 1914 – 18 June 1973), and Princess Catherine Ivanovna of Russia ( Pavlovsk 12 July 1915 - Montevideo, Uruguay 14 July 2007).