AceShowbiz - Prince William and Princess Kate have hosted a garden party in Buckingham Palace. The Prince and Princess of Wales were joined by the Duke and Duchess of Edinburgh the event on Tuesday, May 9, afternoon as the bash marks the first public outing for King Charles' "slimmed down" monarchy.

King Charles was widely reported ahead of his coronation on 6 May to want to head up a leaner royal family made up of senior working royalty.

Princess Catherine, 41, and her husband Prince William, 40, teamed up with Duchess Sophie, 58 and Prince Edward, 59, to take the lead at the garden party, designed to acknowledge the work of volunteers across Britain. Catherine greeted 500 champions at the event and thanked them for their hard work.

It came after she, William and their three children, Prince George, nine, Princess Charlotte, eight, and five-year-old Prince George. took part in "The Big Help Out" event in Slough that saw people pitching in to help communities up and down the U.K.

Royal expert Richard Fitzwilliam told MailOnline Charles had used his coronation portraits, which were released on Monday, to make a nod to his desire for the monarchy to be seen as more slimline and hard-working amid Britain's cost of living crisis.

He said, "This one is a strong forceful portrait of a monarch who knows his own mind and is very experienced."

Richard stressed the Princess Royal"s closeness to Charles in the royal group portrait was "no accident" as she is an “experienced and hard-working" member of the family. He also noted the family image included only four people under the age of 70, with reports also saying Charles is intent on sealing the long-term future of the monarchy by presenting it as modern and relevant.