Prince William tonight spoke of the close ties between Britain and France and said despite Brexit the "depth of our friendship" will not change.
The Duke of Cambridge spoke out in Paris, during an official visit with his wife Kate after earlier being greeted by President Hollande.
William, speaking at the British Embassy dinner, said, "This partnership will continue despite Britain's recent decision to leave the European Union.
"The depth of our friendship and the breadth of our cooperation will not change."
He said, "The connections between our nations run deep – ties of history, ties of values, ties of friendship and family.
"And ties born, above all, of the fact that our countries are neighbours.
"So much of our countries’ histories, culture and language are intertwined. Those ties of neighbours which run through our history are as powerful today as they have ever been.
"Most fundamentally, our nations share a set of common values: democracy, free speech, the rule of law, among many others," he said.
He went on, "I have been reminded over the last few years, as Catherine and I have attended commemorations of the two World Wars, how much we have experienced together and have stood together in moments of great crisis.
"Our relationship is just as strong and enduring today. Our hearts went out to the people of France when you responded so bravely to the awful terrorist attacks of the last two years.
"I was very proud personally to have been present at the England-France football match just days after the Bataclan.
"Our intelligence agencies and security forces are working together night and day to counter the continuing threats.
"Our armed forces are working more closely together than they have ever done – over the skies of Syria and Iraq, or here in Europe.
"And our Governments work closely together to resolve some of the world's most complex issues – whether in the Middle East, Africa or elsewhere.
"This deep friendship between the United Kingdom and France, forged in sweat and blood, is one that will endure.
"Our relationship is greater, of course, than security and global partnership.
In the opulent surroundings of the ambassador’s residence, the Duke and Duchess of Cambridge met a cross-section of young French people, from athletes to musicians and business entrepreneurs.
William went on, "It is a pleasure for Catherine and me to be here this evening, in this beautiful, elegant, and global city.
"As the Ambassador said, Catherine and I have been honoured to meet many of you tonight.
"You have all been invited because you remind us that our two nations also share something else in common: talented, creative young people who are already shaping the world around us – whether in science, music, film, commerce, politics, sport, academia – I could go on, as this list touches practically every area of our national lives.
"Like all neighbours, sometimes our two nations encourage each other through mutual support.
"Sometimes we attempt to outdo the other through rivalry - as we will see tomorrow when Wales play France at the rugby. But always our two nations continually inspire one another to become better: more creative, more prosperous, more innovative.
"So I am proud to be here this evening with you to launch Les Voisins to recount those ties and to strengthen them even further.
"Before I came here, Her Majesty The Queen reminded me of how much she has enjoyed her many visits to France.
"It is a feeling that Catherine and I entirely share, and look forward to this and many more visits in the years to come – to France our ally, our friend, our neighbour."
William finished speaking French. He said, "C’est vraiment un plaisir d’être ici à Paris ce soir. Bonne soirée."
The couple were greeted by the ambassador, Lord Llewellyn of Steep – David Cameron’s former chief of staff in Downing Street – they listened as a singer, Elodie Frege (acutes on both Es) performed to guests.
The duke spoke to a group of athletes, including Colonel Bertrand Gebuhrer, the leader of the French Invictus team, who managed to get himself confused about whether it was William or Harry who launched the Paralympic games for wounded servicemen and women.
After he suggested that it was William’s idea, the duke replied: “As much as it pains me, I have to give my brother credit for that.” The Colonel admitted: “I made a mistake.”
The couple also met Tony Stones, the grounds manager at the Stade de France who has prepared the pitch for tomorrow’s Six Nations match.
“He was asking how the pitch was,” said Mr Stones. “I said, ‘It’s as good as it was at Wembley.’”
As to whether there was any frostiness between William and Kate, opinions were divided. Some thought they looked perfectly happy and relaxed in each other’s company, while another observer said: “She is furious with him.”