Vatican City, Rome, Italy. 14th April, 1951. Princess Elizabeth (later Queen Elizabeth II) and the Duke of Edinburgh flanked by Monsignor Nardone of the Papal Ceremonial, Knights of the Cape and Sword and Swiss Guards as they move through the halls of the [Getty Images]

Vatican City, Rome, Italy, 14th April, 1951, Princess Elizabeth (later Queen Elizabeth II) and the Duke of Edinburgh flanked by Monsignor Nardone of the Papal Ceremonial, Knights of the Cape and Sword and Swiss Guards as they move through the halls of the Vatican Palace to the apartment of Pope Pius XII (Photo by Popperfoto via Getty Images/Getty Images) — see more

Vatican City, Rome, Italy, 14th April, 1951, Princess Elizabeth (later Queen Elizabeth II) and the Duke of Edinburgh flanked by Monsignor Nardone of the Papal Ceremonial, Knights of the Cape and Sword and Swiss Guards as they move through the halls of the Vatican Palace to the apartment of Pope Pius XII (Photo by Popperfoto via Getty Images/Getty Images)