(CNN) -- Two of the world's best-known public figures, Pope Francis and Britain's Queen Elizabeth II, met for the first time Thursday in Rome.
The Queen, accompanied by husband Prince Philip, is paying a one-day visit to Italy at the invitation of Italian President Giorgio Napolitano.
She and the Duke of Edinburgh attended a lunch hosted by Napolitano, whose role as head of state is largely symbolic, at the presidential palace before heading to Vatican City.
The private audience with Pope Francis was the first meeting between the 87-year-old queen, who is Supreme Governor of the Church of England, and Pope Francis, head of the Roman Catholic Church.
But she has met some of his papal predecessors.
According to Vatican Radio, Thursday's audience marked the queen's seventh encounter with a pontiff and the fifth different pope she has met. Besides trips to Rome, she also welcomed Pope John Paul II and Benedict XVI, now Pope Emeritus, on their respective visits to Britain.
Her first papal encounter was with Pope Pius in 1951, the year before she ascended the throne, the broadcaster said.
The Queen's latest visit to Italy, at the invitation of Napolitano, was initially planned last year but was postponed because of illness.
Britain's ambassador to the Holy See, Nigel Baker, told Vatican Radio the Queen had decided to take advantage of the rescheduled trip to meet Pope Francis.
"If you look back in terms of Queen Elizabeth's reign, it is extraordinary how far the relationship between Britain and the Holy See, and between the Anglican Church and the Catholic Church, has developed since 1952 when she became queen," he said.
A key aspect of that has been her several encounters with different popes over the years, Baker said.
Francis, who's from Argentina, was elected pope in March of last year after Benedict took the almost unprecedented step of resigning from the papacy.
Britain and Argentina have a sometimes testy relationship, thanks to an unresolved dispute over the Falkland Islands. The two countries went to war over the South Atlantic territory in 1982 after the then-military government in Argentina landed troops on the islands, which Argentinians call Las Malvinas.