The King and Queen Consort will make their first state visits to France and Germany in a six-day trip at the end of this month, Buckingham Palace announced.
The King will be the first British monarch to give a speech from France’s senate chamber, to senators and national assembly members.
Charles and Camilla will travel to the French capital Paris on 26 March and then continue onwards to Berlin in Germany during the six-day visit.
The Europe-centred visit comes just days after the King welcomed EU chief Ursula von der Leyen to Windsor Castle after she agreed to a historic post-Brexit deal for Northern Ireland.
There are a number of firsts, reflecting what is believed to be the wish of the host countries to mark the historic trip of the nation's new head of state.
A Buckingham Palace spokesperson said: “The visit will celebrate Britain’s relationship with France and Germany, marking our shared histories, culture and values.
“It will also provide an opportunity to look forwards and demonstrate the many ways the UK is working in partnership with France and Germany, whether that be to tackle climate change; respond to the conflict in Ukraine; seize trade and investment opportunities or share the best of our arts and culture.”
While in France, the King and Queen Consort will split their time between Paris and Bordeaux.
Their majesties will join French president Emmanuel Macron and his wife Brigitte for a wreath-laying ceremony at Arc de Triomphe before the King addresses senators and members of the National Assembly at the French senate.
It is still being decided whether the monarch will address the chamber in French as his late mother did in previous visits.
Their majesties will be guests of honour at a State Banquet hosted by president and Mrs Macron at the Chateau de Versailles.
Bordeaux, home to the largest number of British residents in France, will also receive the King and Queen where their majesties will mark the opening of the new British embassy and meet members of the local French and British communities.
It is understood that the King will visit a location in south Bordeaux scorched by devastating wildfires last year, and will meet firefighters and emergency workers as well as meet residents impacted by the incident.
The royal couple will also tour an organic vineyard, which has pioneered a sustainable approach to wine making, including generating its own solar energy and capturing and converting the carbon dioxide it produces.
The King and Queen Consort will arrive in Germany on Wednesday 29 March to a ceremonial welcome from president Steinmeier and Frau Budenbender at the Brandenburg Gate.
Their majesties will be guests of honour at a State Banquet, given by the president and his wife at the Schloss Bellevue. They will later visit the Bundestag, the German federal parliament, where His Majesty will address the House - a first for a British monarch.
His Majesty will meet refugees recently arrived from Ukraine and hear about the support Germany provides for them.
On the anniversary of the war in Ukraine, King Charles praised the “remarkable courage and resilience” of the Ukrainian people, saying that they had “suffered unimaginably”.
During the trip, their majesties will also visit Hamburg accompanied by the president and Frau Büdenbender, where they will take a moment of reflection as they attend the St. Nikolai Memorial - the remains of a church which was destroyed when the Allies bombed Hamburg during the Second World War.
In a poignant gesture, His Majesty and the president will lay wreaths during a short ceremony of remembrance.
The King and Queen Consort end their visit with a celebratory reception with Hamburg residents and members of the local British community, accompanied by the President and Frau Büdenbender.
The announcement of the state visit comes days after Prince Harry and Meghan confirmed that they’ve been asked to leave their UK home, Frogmore Cottage.
It was reported that King Charles III offered the keys to the cottage to the Duke of York. Reports have also said that Harry and Meghan are making plans to remove their remaining belongings from the home.
