King Charles and Pope Leo prayed together in the Vatican's Sistine Chapel on Thursday, in the first joint worship including a British monarch and a Catholic pontiff since King Henry VIII broke away from Rome in 1534.
Latin chants and English prayers echoed through the chapel, where Leo was elected the first US pope by the world's Catholic cardinals six months ago in front of frescoes by Michelangelo depicting Christ delivering the Last Judgment.
Charles, supreme governor of the Church of England, was seated at the pope's left near the altar of the chapel as Leo and Anglican Archbishop Stephen Cottrell led a service that featured the Sistine Chapel Choir and two royal choirs.
Although Charles has met the last three popes, and Popes John Paul II and Benedict XVI travelled to Britain, their previous encounters never included joint prayers.
The King and Queen Camilla are on a state visit to the Vatican marking the closening ties between the Catholic Church and Anglican Communion, five centuries after their turbulent separation.
“There is a strong sense that this moment in the extraordinary setting of the Sistine Chapel offers a kind of healing of history," Anglican Rev. James Hawkey, canon theologian of Westminster Abbey, told Reuters.
"This would have been impossible just a generation ago," he said. "It represents how far our churches have come over the last 60 years of dialogue."
Archbishop Cottrell, the Anglican Archbishop of York, stood in at the Sistine Chapel service for Sarah Mullally. She was recently announced as the first woman to serve as Archbishop of Canterbury, the spiritual head of the Anglican Communion, but will not take the role until next year."
Earlier on Thursday, Charles and Camilla’s state limousine swept through St Peter’s Square where crowds traditionally gather to see the Pope and made their way to San Damaso Courtyard, the ceremonial entrance to the Apostolic Palace, the pontiff’s official residence.
Waiting to greet them was Reverend Monsignor Leonardo Sapienza, Regent of the Prefecture of the Papal Household, and a guard of honour provided by the Vatican’s famous Swiss Guard.

Drawn from Swiss citizens who are Catholic, the guard has been providing protection for the head of the Catholic Church for centuries.
The royal couple stood as the national anthems of Britain and the Vatican City were played. They also met a group of Papal Gentlemen.
The Queen wore a traditional black outfit to meet the Pope, including a veil over her head and shoulders. Her silk dress was by Fiona Clare, milliner Philip Treacy made the mantilla or veil, and she wore the late Queen’s “raspberry pip” brooch in the shape of cross.
The state visit to the Holy See, the government of the Roman Catholic Church in the Vatican, is understood to be deeply significant for the King personally and will celebrate the Papal Jubilee, held every 25 years.