Britain's King Charles III and Pope Leo XIV have prayed together in the Vatican's Sistine Chapel, in the first joint worship including an English 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 six months ago in front of frescoes by Michelangelo depicting Christ delivering the Last Judgement.
Charles, supreme governor of the Church of England, sat 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, said.
"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.
The split between the Catholic Church and the Church of England was formaliSed in 1534, after Pope Clement VII refused to annul King Henry VIII's marriage to Catherine of Aragon.
Henry's desire for a male heir - and a new wife who might provide one - was the immediate catalyst, but other factors were also at play, involving the English crown's seizure of church assets and the growth of Protestant ideas in England.
As England swung between Catholicism and Protestantism during the reigns of Henry's daughters Mary I and Elizabeth I, hundreds of Catholics and Protestants were executed for their faith, often burned at the stake.
King Charles and Queen Camilla, who visited the Vatican earlier this year to see Pope Francis, also had a private meeting with Pope Leo this morning.
The King will travel in the afternoon to Rome's Basilica of St Paul Outside the Walls, one of Catholicism's four most venerated churches, where Leo has approved giving him a new title of "Royal Confrater", or brother, at the connected abbey.
Charles will also be gifted a special seat in the apse of the basilica. The wooden chair, reserved in the future for use only by British monarchs, is decorated with the king's coat of arms and the ecumenical motto "Ut unum sint" (That they may be one).
King Charles has visited the Vatican several times and met privately with Pope Francis on 9 April, days before he died.
The monarch also met two of his predecessors - Pope Benedict XVI and Pope John Paul II.
His son Prince William attended the funeral of Pope Francis and his brother, Prince Edward, was at Pope Leo's inauguration mass.
The visit comes as the Catholic Church celebrates the Jubilee, a year-long event held every 25 years which has drawn millions of pilgrims to the Vatican.
Bishop Anthony Ball, the official Anglican representative to the Vatican, said the honours being bestowed on King Charles "show the commitment that both of our Churches have to working for a shared future."
Buckingham Palace announced that King Charles had also approved two British honours for Pope Leo: making him the "Papal Confrater" of St George's Chapel, Windsor Castle and conferring on him the Knight Grand Cross of the Order of the Bath.
