In pictures: King Charles III's coronation weekend

King Charles III and Queen Camilla have shared their "most sincere and heartfelt thanks" in a new message from the monarch released by Buckingham Palace today, as the coronation long weekend comes to an end.

In addition to the King's message of gratitude, the palace released four new official photographs of the King, Queen and members of the royal family taken after the historic coronation service.

All were taken by renowned British photographer Hugo Burnand at Buckingham Palace.

This portrait shows the King photographed in the palace's Throne Room dressed in the full regalia – the Robe of Estate and the Imperial State Crown while holding the Sovereign's Orb and Sovereign's Sceptre with Cross.

He is seated on one of a pair of 1902 throne chairs that were built for use at King Edward VII's coronation by future King George V and Queen Mary.

Queen Camilla was photographed wearing Queen Mary's Crown and Robe of Estate in the Green Drawing Room.

In his message of thanks, King Charles wrote that he and his wife wanted in particular to pay tribute to those who helped make events in London, Windsor and beyond "as happy, safe and enjoyable as possible."

"To those who joined in the celebrations - whether at home, at street parties and lunches, or by volunteering in communities - we thank you, each and every one," the newly-crowned sovereign wrote.

"To know that we have your support and encouragement, and to witness your kindness expressed in so many different ways, has been the greatest possible Coronation gift, as we now rededicate our lives to serving the people of the United Kingdom, the Realms and Commonwealth."

The King and Queen also sat for a portrait together in the Throne Room.

London-based photographer Burnand has long held close ties to the royal family, having previously taken the official photos for both Charles and Camilla's wedding in 2005, and William and Kate's wedding in 2011.

He's also been privately taking photographs of Charles and Camilla for over two decades.

Burnand also took several photos of the King and Queen released by the palace ahead of the coronation.

A fourth photograph was released of the King and Queen flanked by "working royals" – members of the family who carry out official duties on behalf of the monarch.

Here, King Charles III and Queen Camilla are pictured with members of the working royal family, (from left) Prince Edward, the Duke of Kent; Birgitte, Duchess of Gloucester; Prince Richard, the Duke of Gloucester; Vice Admiral Sir Tim Laurence; Princess Anne; Prince William, the Prince of Wales; Kate, the Princess of Wales; Sophie, the Duchess of Edinburgh; Princess Alexandra, the Honourary Lady Ogilvy; and Prince Edward, the Duke of Edinburgh; in the Throne Room at Buckingham Palace.

As Britons celebrated another public holiday on Monday for the coronation, they were encouraged to take part in some volunteer work.

The Waleses were front and centre for the Big Help Out, lending a hand to renovate the Upton Scouts Hut in Slough.

It's not clear just how "big" of a help five-year-old Prince Louis was here on the excavator with his dad, Prince William.

Princess Charlotte tried her hand at archery while taking part in the Big Help Out.

Louis also lined up with the bow and — well — not so much arrow as suction cup.

Things seemed to be a bit more serious for the will-be heir, Prince George, who was handed a drill to help out with some woodwork.

Exploring his artistic side, Prince Louis used his hand to make paint decorations on a wall.

Back outside, he wasn't afraid of getting his hands dirty with some time on the shovel.

He also seized control of the royal wheelbarrow on a day featuring 8 million volunteering roles across the country.

Luckily mum Kate, Princess of Wales, was on hand to help with the barrow once it was full and heavy.

Prince George didn't miss out on a chance to run the digger through its paces.

The royals were among 6 million Britons planning to get involved with some form of volunteering on Monday, according to the Big Help Out.

Princess Charlotte and Prince George seemed to take their time considering what was next up on the schedule.

Louis seemed a bit unsure too as his mum pointed something out to him.

Kate led the way as two of her kids and several scouts marched through the green grass.

All those worries from earlier seemed to float away walking hand-in-hand with mum.

It wasn't all fun and games for Princess Charlotte, who tried her hand at some painting or varnishing.

As the flypast started on coronation day, Prince Louis was seen looking up and then screaming out while on the balcony of Buckingham Palace.

The young royal joined his parents on the Buckingham Palace central balcony after the Coronation service.

Queen Camilla was all smiles after her Coronation with King Charles III, at Buckingham Palace.