Buckingham Palace and the Vatican announced that Pope Francis had a previously unannounced meeting at the Vatican with Britain's King Charles and Queen Camilla during their state visit to Italy.
Doctors prescribed Francis two months of rest after the pontiff experienced a serious bout of double pneumonia, causing Charles and Camilla to postpone their plans.
According to a Vatican statement, the Pope met the royal couple privately on Wednesday afternoon and offered his best wishes for their 20th wedding anniversary, which they were celebrating.
Buckingham Palace said Charles and Camilla "were delighted the Pope was well enough to host them - and to have had the opportunity to share their best wishes in person."
As British monarch, Charles heads the Church of England, which split from the Catholic Church in 1534.
Francis and Charles met twice before Charles became king in 2017 and 2019. The late Queen Elizabeth II visited Francis at the Vatican in 2014.
With AAP.