King Charles III has found himself at the center of a crisis of faith—and conscience—after joining Pope Leo XIV and the Archbishop of Canterbury for a prayer service inside the heart of Roman Catholicism, as CNA reports.

On October 23, the monarch participated in an unprecedented joint prayer alongside the Catholic pontiff and Anglican Archbishop Stephen Cottrell inside the Sistine Chapel at the Vatican, offending Protestant leaders who argue the ceremony violated Charles’s coronation oath to uphold the Protestant faith.

Attended by Queen Camilla and surrounded by centuries of religious and political tension, the moment might have been meant as a gesture of unity—but it didn’t land that way back in Northern Ireland, where Protestant hardliners see it as a betrayal wrapped in incense.

First Royal-Papal Prayer Since the Reformation

This marked the first time since the Reformation that a sitting British monarch publicly joined a Roman Catholic pope in prayer. Whatever political diplomacy was intended, the reaction from across the Irish Sea was anything but reverent.

Rev. Kyle Paisley, Free Presbyterian minister and son of firebrand figure Ian Paisley, didn’t waste any time. In letters to newspapers and interviews across UK media, he accused Charles of “denying the Christian Gospel” and “giving the lie to his oath.”

“Our king has denied the Christian Gospel, flown in the face of holy Scripture, given the lie to his oath, and shown that he is not at all what he says he is — a true Protestant,” he declared during a BBC interview.

Reformers Roll Over as Vatican Gains Royal Soft Power

Rev. Paisley didn’t stop at the Sistine moment. He pointed to the royals' recent visit to a Requiem Mass for the Catholic Duchess of Kent as further proof of what he called a creeping “Romanist” agenda among Britain’s upper crust.

Calling the October 23 service a “symbolic reversal of the Reformation,” Paisley warned that deep theological divisions should not be papered over “in the name of dialogue.” He specifically contrasted Protestant emphasis on Scripture alone with what he viewed as the Catholic emphasis on Church hierarchy and tradition.

“It is a crying shame that no evangelical Christian MP, or member of the House of Lords, has spoken out publicly about the king’s blatant compromise of his oath,” he added, questioning the silence from the government and royal-aligned elites.

Protestant Institutions Push Back With Sharp Rebuke

The Orange Order wasted no time labeling the meeting with the pope “a sad day for Protestantism.” For those unfamiliar, the group represents generations of Protestant identity and history, especially in Northern Ireland, where religious loyalty can carry national significance.

Wallace Thompson of the Evangelical Protestant Society backed Rev. Paisley’s theological points, noting sharp doctrinal lines that make joint prayer inappropriate. “The issues that were there at the time of the Reformation are still there… the two churches are so far apart,” Thompson said.

He clarified that while the king has the right to meet with anyone, engaging in religious acts with the pope sends the wrong message about his sworn obligations to uphold the Protestant Reformed religion “established by law.”

Symbolism at the Vatican Raises Eyebrows

Paisley also flagged the quiet installation of a royal-emblemed chair in St. Paul’s Basilica as more than ceremonial. “The chair in St. Paul’s Basilica, which has the king’s emblem on it, is not an empty ornament,” he emphasized. “It is there for him to use on any occasion he visits.”

That may sound like detail-oriented paranoia, but in an age where religious posturing has returned to global diplomacy, optics carry weight—and so do oaths made before God and nation.

Kyle Paisley’s critique lands differently coming from someone who, unlike his famously strident father, sent condolences to Catholics after the death of Pope Francis. His tone may be firm, but it’s not fringe—in fact, it echoes real questions about the role of faith in modern monarchy.

Heir and Allies Attend Catholic Ceremonies

Nor is the Vatican connection just about Charles. His son, Prince William, attended Pope Francis’s funeral. Prince Edward, the king’s brother, was present at the inauguration of Pope Leo XIV last May, underscoring a widening royal rapprochement with Rome.

To be clear, the issue isn’t about whether a king can pray next to a pope. The deeper concern is whether such religious gestures compromise the historic and legal commitments made during a coronation, whether Protestantism remains the official religion of the Realm.

It’s fair to ask the question: in pursuing interfaith optics, has King Charles blurred a line no monarch has crossed in over 500 years? For many faithful Protestants, the answer is not only yes—it’s a regretful unraveling of sacred heritage.