Later on Wednesday, the King will become the first UK monarch to deliver a speech to both houses of the Italian parliament.
Part of the speech is expected to be delivered in Italian.
The royal couple will then spend the evening of their wedding anniversary at a state banquet at the Quirinale Palace, an event likely to be a showcase for local food and for a guest list of celebrities and dignitaries.
The King and Queen have been given a warm reception on their trip to Italy, posing for photos on Tuesday as they met crowds outside the Colosseum, near the ancient site of the Temple of Venus.
There were calls of “Carlo” – Italian for Charles – from crowds waiting to see the royal visitors and local media also seemed interested by their car, the claret coloured State Bentley.
Back home at Buckingham Palace, there was a musical tribute to mark the royal couple’s wedding anniversary.
The Royal Family’s official X, external account posted a video which showed guards playing a brass version of Madness’s 1981 hit It Must Be Love.
