King Charles and Queen Camilla not only kick off their state visit to Italy today, but they’re also just 48 hours away from celebrating 20 years of marriage.

Charles and Camilla met over 50 years ago now, and their immediate attraction to one another was palpable; they both married other people, though—Camilla to Andrew Parker Bowles, and Charles to Princess Diana—though, say what you will, that didn’t seem to stop their intense affection for one another. Eventually, both the Parker Bowles marriage and the union between the former Prince and Princess of Wales ended in the mid-1990s, and Charles and Camilla finally tied the knot on April 9, 2005.

Longtime royal photographer Arthur Edwards told The Sun that Camilla makes Charles a better man. “I have seen their marriage up close and, in my opinion, it is an extremely happy union,” he said, adding that “it has become very obvious that they make each other feel very happy and secure.”

“The main thing I’ve noticed is that the King, who I have been photographing for nearly 50 years, has become a nicer person,” Edwards added. Though he admitted that the King still gets worked up sometimes—who can forget the leaky pen?—Camilla “soothes the situation,” and “thanks to Camilla, he has calmed down. These days he rarely gets stressed or wound up about things.”

He continued, “In the past, he would get angry if the windows were shut or there was no air in the room. All that pent-up anger seemed to disappear after he tied the knot with Camilla.”

Edwards is aware that the King and Queen’s marriage isn’t perfect—“Like all couples, they have the odd disagreement, Edwards said, adding that “It is only natural”—but, he said, “unlike during his marriage to Diana, there is laughter even in the midst of an argument.”

“They both have a history of unhappy marriages behind them and are determined that it is never going to happen again,” he said, adding that “The best thing Charles and Camilla ever did was get married” and “It has been one of the happiest royal marriages ever.”

Charles and Camilla’s royal tour of Italy kicks off April 7, and they’ll spend their actual anniversary, April 9, as guests of honor at a state banquet in Rome, according to The Independent. Among other prominent figures in Italian society, they’ll be joined at the black-tie dinner by its host, Italy’s President Sergio Mattarella.

Elsewhere in the visit, there will be a wreath laying at the Tomb of the Unknown Soldier, and in Ravenna the couple will attend a reception in the Town Hall, marking the 80th anniversary of liberation from Nazi occupation by Allied Forces, according to Town and Country. They’ll meet farmers whose land and crops have been severely affected by floods, and Buckingham Palace said of the visit that it will “underscore the depth and breadth of the bilateral relationship: our defense relationship including in the current international context; our shared values, history, and culture; our work together on the clean energy transition; and the links between our peoples and communities.”

A planned visit to see Pope Francis at the Vatican has been postponed as the Pope recovers from a five-week bout with pneumonia; it was due to be Charles’ first meeting with the Pope as King and head of the Church of England. That said, he will still make history during the visit, as Charles will become the first British monarch to address both houses of the Italian parliament while there.