Royalty, Greece, pic: circa 1920's, The Greek Royal family, back, left-right, Prince Andreas, father of the Duke of Edinburgh, Princess Marie, Prince Christoph and Prince Nicolaus, father of the Duke of Kent, Seated, left-right, Prince George, brother of George I, Queen Olga, King Constantine (Photo by Popperfoto/Getty Images)

Royalty, Greece, pic: circa 1920's, The Greek Royal family, back, left-right, Prince Andreas, father of the Duke of Edinburgh, Princess Marie, Prince Christoph and Prince Nicolaus, father of the Duke of Kent, Seated, left-right, Prince George, brother of George I, Queen Olga, King Constantine  (Photo by Popperfoto/Getty Images)