The King has given President Emmanuel Macron a book containing photographs of the pair together as they held talks on the opening day of the state visit to France.
Charles and Camilla are visiting Paris and Bordeaux, six months after the trip had to be rescheduled because of widespread rioting across the country.
As well as the photograph album, the King gave Mr Macron a complete edition of Voltaire’s writings when he visited the Elysee Palace, the president’s official residence, on Wednesday afternoon.
The works have been edited by Professor Nicholas Cronk, a leading UK academic at Oxford University and director of the Voltaire Foundation.
Started in 1968, the complete works, comprising 205 volumes, was only completed in April 2022 and included Letters on the English, a series of essays by the French Enlightenment writer and philosopher, based on his experiences living in Britain between 1726 and 1729.
In return, Mr Macron gave the King a golden coin featuring Charles’s portrait, as well as a prize-winning French novel.
The pair arrived at the Elysee together by car, closely followed by the Queen and the president’s wife Brigitte Macron.
The couples exchanged pleasantries as they stood at the end of a red carpet in the palace courtyard, laughing together.
Mr Macron appeared particularly animated, chatting with the gathered media.
As they entered Mr Macron’s lavishly decorated office, Charles jokingly asked if the waiting photographers were always there.
The King and president left the building, deep in conversation, to plant an oak tree which was also given by Mr Macron.
Camilla wore a dusky pink, wool crepe coat-dress by Fiona Clare, and a pink beret-style hat by milliner Philip Treacy.
The couple had earlier landed at Paris Orly airport, where they were greeted with a guard of honour from an officer and 20 guardsmen of the Republican Guard, which is part of the French National Gendarmerie.
They then attended a ceremony of remembrance and wreath-laying at the Arc de Triomphe in the centre of the capital.
Charles symbolically lit the monument’s eternal flame, which burns in memory of those who died in the First and Second World Wars.
It was the first time in 30 years the ceremony has been included in a state visit.
Charles and Camilla were seen exchanging warm words with Mr and Mrs Macron throughout the ceremony.
The French and British national anthems were played and there was a flypast by the Patrouille de France and Red Arrows before the couples travelled down the Champs Elysees by car.
On Wednesday evening, Charles and Camilla will be guests of honour at a black tie state banquet hosted by the Macrons in the Palace of Versailles’ Hall of Mirrors.
Both the King and Mr Macron will address the 160 guests, who will include high-profile figures chosen for their contribution to UK-France relations.
The majority of the original royal programme has been retained but a few new elements have been added, including the Queen and Mrs Macron launching a new Franco-British literary prize at the Bibliotheque Nationale de France.
Charles will become the first British monarch to give a speech from France’s senate chamber on Thursday.
Other highlights include the royal couple meeting sports stars as France hosts the Rugby World Cup.
When the couple travel to Bordeaux, home to 39,000 Britons, they will meet UK and French military personnel to hear about how the two nations are collaborating on defence.
The planned tour in March was to be their first state visit, but it was postponed at the last minute after violent nationwide demonstrations by those opposed to Mr Macron’s retirement age reforms.
Bordeaux’s town hall was set on fire by protesters just a few days before the trip was due to begin.
