The Duke and Duchess of Edinburgh were in place of the monarch at the ceremony to celebrate Anglo-French relations, marking the 120th anniversary of the Entente Cordiale.

The Entente Cordiale was a series of agreements signed between the two nations in 1904 - while not a formal alliance, it served as the foundation for an enduring relationship between the countries.

Edward and Sophie inspected the troops from both nations as they represented the King, who continues his cancer treatment.

Joined by General Sir Patrick Sanders, UK chief of general staff, the French chief of army staff General Pierre Schill, and France's ambassador to the UK Helene Duchene, the event was the first time a non-Commonwealth country took part in the Changing of the Guard ceremony.

However, the French troops did not guard the royal residence.

The royals walked past 32 members of the 1st and 2nd infantry regiments of the Republican Guard and then 40 guardsmen from F Company Scots Guards, lined up opposite their French counterparts.

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Major Jamie Drummond-Moray, officer commanding F Company Scots Guards, said: "It is an enormous privilege for us to host the French here in London and to play such a significant part in a ceremony that has never happened before with a non-Commonwealth country.

"It really is a monumental occasion and more so given that it is marking 120 years of the strong relationship between the UK with France.

"I think it's a great honour for all our soldiers, and a fantastic day for everyone in France and the UK."