Charles arrived in Paris on Wednesday for a three-day state visit, in a show of pageantry and symbolism meant to turn the page on years of rocky relations between the two nations since Britain voted to leave the European Union.

“Together, our potential is limitless,” Charles said in flawless French, giving the first speech by a British monarch to representatives of both houses of the French parliament.

“That’s why we must cherish and take care of our entente cordiale. For future generations, so it becomes an entente for sustainability to tackle more efficiently the global urgency in terms of climate and diversity,” he said.

The so-called Entente Cordiale was an alliance dating from 1904 that put a stop to centuries of military rivalries between France and Britain to see the two European powers fight on the same side during two world wars.

With Russia’s “unjustified aggression” in invading Ukraine 18 months ago, the two countries were once again facing war on the continent, he said.

“Together, we are unshakable in our determination that Ukraine will prevail,” Charles said.

The warm words, visits and symbolic gestures come after several tense years over the negotiation of Britain’s exit in 2020 from the European Union, and after that, rows over issues ranging from immigration to the sale of submarines.

Former British Prime Minister Liz Truss once said the jury was out on whether France was a friend or foe, before settling on calling it a friend last year. Her successor, Prime Minister Rishi Sunak, visited France in March to kick off what he called an “entente renewed”.

“We must reinvigorate our friendship so that it is up to the challenges of the 21st century,” Charles said in a toast at a state banquet held at the Palace of Versailles the day before.

Later on Thursday, Charles, together with his wife Queen Camilla, French President Emmanuel Macron and his wife Brigitte, will visit Notre-Dame cathedral in Paris to view restoration works following a massive blaze in 2019 that destroyed its roof.

The king is keen to walk in his mother footsteps and has referred to Elizabeth’s deep affection for France.

By Michel Rose and Dominique Vidalon

(Reporting by Michel Rose; Editing by Sharon Singleton)