In 1980, Queen Elizabeth II made history by becoming the first British monarch to make a state visit to the Vatican.* Since the Vatican prohibits any non-Catholic women from wearing anything except black, Her Majesty was dressed in a long black taffeta gown. The pope welcomed the Queen and the Duke of Edinburgh at the door of his private library.
Thus met two greatest non-elected statesmen of 20th century. In 1982, John Paul would be welcomed by Her Majesty at Buckingham Palace during a historic visit to Great Britain. [However, it was made clear this would not be a state visit but one “to the Roman Catholic community in Great Britain”]. The Queen visited the Vatican again in 2000 to mark the 20th anniversary of their first meeting.
*She meet Pope Pius XII as a princess and Pope John XXIII on a state visit to Italy.