The King is sending well-wishes to the Pope following his cancer diagnosis while UK religious leaders have urged prayers for the pontiff.
Charles, who is still undergoing treatment for cancer himself, and the Queen met Pope Leo XIV last year during a state visit to the Vatican.
The Pope’s health condition was confirmed on Tuesday after the Vatican said he had undergone a “successful” planned surgery to remove the lower lobe of his right lung.
Lung adenocarcinoma is a common type of lung cancer.
The Press Association understands the King is writing privately to the Pope to pass on his well-wishes.
The monarch and the Pope made history in 2025 when they prayed together in the Vatican’s Sistine Chapel in a symbolic moment of unity for Anglicans and Roman Catholics across the globe.
It was the first time a British monarch, the Supreme Governor of the Church of England, had prayed at a public service with the Pope, head of the Catholic Church, since the Reformation.
The King with the Pope in St Peter’s Square in October last year (Aaron Chown/PA)
PA Archive
The Vatican has cancelled all the Pope’s audiences through to October 20.
The 71-year-old is said to have spent a calm night in the Gemelli Hospital in Rome following his surgery.
The leader of Catholics in England and Wales, Archbishop Richard Moth has asked people to pray that the Pope “may be restored to full health after a period of rest and recuperation”.
The Archbishop of Westminster and president of the Catholic Bishops’ Conference of England and Wales (CBCEW) said there was a sense of “gratitude and relief” on confirmation that the surgery had been successful.
He added: “We now know that Pope Leo was diagnosed with lung carcinoma and, in this month of the Holy Rosary, we entrust his recovery to the maternal care of Our Lady Health of the Sick.
“I ask that Catholics in England and Wales, and indeed all people of goodwill, pray for Pope Leo – in our homes and in our parishes – that he may be restored to full health after a period of rest and recuperation.
“We also remember all those who are experiencing illness at this time, and keep them, their families and those who care for the sick in our prayers.”
The Church of England’s top bishop also said she is praying the Pope’s “recovery will be swift”.
Archbishop of Canterbury Dame Sarah Mullally, who travelled to Rome to meet the Pope in April, said he is in her daily prayers.
She said: “My daily prayers remain with Pope Leo XIV following his cancer diagnosis, and I assure the Holy Father and the Catholic faithful of the prayers of the Church of England and the Anglican Communion.
“I pray that the Holy Spirit – the Comforter, Healer and Giver of Life – will sustain him in the days and weeks ahead, and that his recovery will be swift and complete.”
Dame Sarah Mullally met Pope Leo at the Vatican in April (Vatican Media/PA)
PA Media
Dame Sarah, in the hours after her meeting with the pontiff, had hailed it “a significant moment”, describing the experience as warm, encouraging and hopeful.
She assured the Pope of a “warm welcome from the Church of England should you honour the United Kingdom with a visit”, and offered him gifts including a jar of honey made from nectar from beehives in Lambeth Palace Garden in London.
The Pope commented “still a nurse” when Dame Sarah handed it to him, referring to her previous career as chief nurse in England.