King Charles III and Pope Leo XIV will become the first British monarch and the first pontiff to pray together in a religious service since the Reformation of the 16th century.

This historic moment will take place in the Sistine Chapel at the Vatican, during their state visit next week. King Charles and Queen Camilla.

Under the chapel's famous ceiling, painted by Michelangelo, the service will bring together clergy and choirs from both the Roman Catholic Church and the Church of England, of which the king is supreme governor.

The visit will be seen as an important symbol of reconciliation, on a trip that will also see the first meeting between the king and the new American-born pope.

State visit

The state visit to the Vatican was rescheduled after the previous one was postponed due to the ill health of Pope Francis, Leo's predecessor.

The British monarchs held a private meeting with Pope Francis in April to mark the royal couple's 20th wedding anniversary, in one of the late pope's last encounters with high-profile visitors before his death on April 21.

The state visit, which will take place on April 22 and 23 October, will feature a series of meetings and services highlighting the cordial relations between the Church of England and the Catholic Church.

Charles and Camilla will meet the Pope and senior Vatican officials, and a special ecumenical service will be held, uniting the Catholic and Anglican traditions, with the King and the Pope praying together.

The service in the Sistine Chapel will focus on the protection of nature, in recognition of the King's enthusiastic support for environmental causes.

Its purpose will be to showcase the harmony between the two faiths, with the Sistine Chapel Choir singing alongside the Choir of St. George's Chapel and Her Majesty's Chapel Royal Choir.

The richly decorated 15th-century chapel,It is the scene of the conclave of cardinals that elects the Pope.

Meetings between monarchs and pontiffs have taken place before, including those of the late Queen Elizabeth II.

But according to Buckingham Palace and the Church of England, there has not been a similar moment, with a British monarch and Pope praying together in a shared church service, since Henry VIII's split from Rome in the 16th century.

Royal sources have stressed the historical significance of this occasion, with the king having a long-standing commitment to building bridges between faiths.

Another centenary event

There will be another connection to the pre-Reformation era when King Charles attends a service at St. Paul Outside the Walls Church.

This church and abbey, which houses the tomb of St. Paul, was traditionally associated with the English monarchy, dating back to the days of medieval rulers and Anglo-Saxons who once contributed to the upkeep of this building in Rome.

The insignia of the Order of the Garter has been displayed here for centuries, reflecting its links with the English monarchy.

The monarch will adopt an honorary and spiritual title associated with the abbey, becoming what is called a “Royal Brotherhood,” as part of the abbey’s brotherhood.

A spokesman for the Church of England said the title is a tribute to the King’s “work over decades to find common ground between faiths and bring people together.”

Charles III will sit in a seat designed specifically for the purpose, decorated with the King’s coat of arms, which will remain in place for his and his successors’ future use.

State visits are made on behalf of the government, and a spokeswoman for the UK Foreign Office said: “The Catholic Church is the largest denomination of the world’s largest religion.”

By In this way, the visit of the kings "will strengthen the United Kingdom's relationship with this influential and crucial partner," he added.