Olga Constantinovna of Russia (3 September [O.S. 22 August] 1851 – 18 June 1926) was Queen of Greece as the wife of King George I. She was briefly the regent of Greece in 1920. A member of the Romanov dynasty, Olga was the oldest daughter of Grand Duke Constantine Nikolaievich and his wife, Princess Alexandra of Saxe-Altenburg. She spent her childhood in Saint Petersburg,... Wikipedia