Britain's King Charles III looks on as he prepares to deliver a speech at the Italian Parliament, in Rome, on April 9, 2025, as part of a State visit in Italy. Ian Vogler, AFP

ROME, Italy -- Britain's King Charles III told Italy's parliament Wednesday that peace is "never to be taken for granted," saluting shared values and a history of sacrifice between the two countries in a historic address.

The king's speech, the first by a UK monarch to a joint session of Italy's two legislative chambers, came as he celebrated his 20th wedding anniversary with wife Camilla during a state visit to Italy.

Speaking in both Italian and English, the 76-year-old monarch, who is recovering from cancer, eulogized Italy as a place "very dear to my heart", having made 18 official visits in over 40 years.

Variously citing Virgil, Dante, and Italy's reunification hero Giuseppe Garibaldi, he called it "one of the pleasures of my life to come to know this irresistible country", as he addressed the Chamber of Deputies packed with parliamentarians.

Although Britain had many differences with Italy, their shared values were seen in countless courageous acts during World War Two, he said.

Charles cited the tens of thousands of Commonwealth soldiers who died during the liberation of Italy from the Nazis, while noting the help offered by Italian civilians, risking their lives.

READ: UK's King Charles III to visit Vatican in April

"Today, sadly, the echoes of those times -- which we fervently hoped had been consigned to history -- reverberate across our continent," he said.

"Our younger generations can now see in the news every day on their smartphones and tablets that peace is never to be taken for granted."

He noted Italy's support today for Ukraine, adding: "Britain and Italy stand today united in defense of the democratic values we share."

Speaking on the environment, a personal passion, the king noted that warnings he gave while addressing a parliamentary meeting in Rome 16 years ago were "depressingly being borne out by events".

"From the droughts in Sicily to the floods in Somerset, both our countries are already seeing the ever more damaging effects of climate change," he said.

Parliamentarians gave Charles a standing ovation when he mentioned a tribute his mother, Queen Elizabeth, gave in Italy in 1992 to murdered anti-mafia judge Giovanni Falcone.

He elicited laughter when he reminded his audience that Garibaldi had a British biscuit named after him -- "the ultimate mark of British esteem".

READ: Cancer-hit UK king hails doctors in Christmas speech

- 'How impressive is a king?' -

Earlier Wednesday, Charles had a short private meeting with Prime Minister Giorgia Meloni, the leader of Italy's hard-right government, within the historic Villa Doria Pamphili surrounded by gardens.

The king was then whisked in his Bentley to Rome's working-class neighborhood of Testaccio, with its converted slaughterhouses now holding cultural events.

There, he met with drama students who performed a portion of Shakespeare's "Othello" in Italian with a famous alumnus of the school, "Inspector Montalbano" actor Luca Zingaretti, in attendance.

A few dozen curious residents milled about outside, but most appeared nonplussed, such as Carlotta, a 70-year-old woman who declined to give her last name.

"I don't give a damn about the king but they've spent three days cleaning the neighborhood, scrubbing the pavements, clearing up dog poo, so he can come every week if he likes," she told AFP.

Another woman, 66-year-old Ninetta, quipped: "Rome has seen emperors, how impressive is a king? I couldn't care less."

Benedetta Ciarlo, 21, was more enthusiastic, having travelled on purpose from Benevento near Naples just to see the king.

"I'm a massive fan of all things royal. My favorite royal used to be Prince Philip, now it's Charles," she said, adding that she appreciated his concern for young people and the future of the planet.

Camilla, meanwhile, spent her morning visiting school children learning English, and  was presented with a pizza Margherita -- named in the 19th century for another queen, Margherita of Savoy.

A stunned pizza delivery woman, Federica Viola, said it was "surreal" when she arrived and saw the queen.

"They ordered a pizza and I didn't understand why, then I figured it out and it was for the queen so it was a huge emotion," she told AFP.

The royals' four-day trip, which included a visit to the Colosseum on Tuesday and on Thursday sees them heading north to Ravenna, comes less than a fortnight after Charles' latest health scare.

He was briefly admitted to hospital after experiencing side effects from his cancer treatment.

A state banquet is planned Wednesday night at the Quirinale, the home of Italy's president, Sergio Mattarella, who is expected to give a toast to mark the royal's anniversary.

© Agence France-Presse