According to Royal News 24:
On this day in 1980, Her Majesty Queen Elizabeth II of the United Kingdom made history by becoming the first British monarch to pay a state visit to the Vatican. The Queen had visited the Vatican before, first as Princess Elizabeth during the pontificate of Pope Pius XII and again in 1962 when she was received by Pope John XXIII. However, the 1980 state visit to the Holy See was a turning point in Anglo-Vatican relations and led to full recognition of the Vatican City state by the UK and the exchange of ambassadors.
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