The Queen welcomed fellow royals to Westminster Abbey for the Commonwealth Day service on Monday afternoon - hours after the Princess of Wales made a personal apology for digitally altering a family photograph.
The King, who is undergoing treatment for cancer, was not attending the service, having postponed all in-person public-facing duties for the time being.
Prince William was seen chatting with the Duke and Duchess of Edinburgh and the Princess Royal as they waited near the Great West Door for the Queen to finish meeting people in the welcoming line.
The prince, making his first public appearance since his wife admitted to "editing" their Mother's Day picture, greeted Edward with a friendly pat on the arm and a kiss on both cheeks, before standing in conversation with his aunts and uncle.
As Camilla approached, William was seen to say “hello” to his stepmother before moving forward to kiss her on both cheeks.
A pre-recorded video message from the King will be played at the Commonwealth Day event.
It comes as Buckingham Palace faces fresh pressure to reveal the truth behind an image of the Princess of Wales and her children after international picture agencies withdrew it over claims it had been digitally manipulated.
The photograph of Kate and her children, taken by the Prince of Wales, was the first to be issued since the princess’s abdominal surgery and was released by the Palace to mark Mother’s Day.
It is understood William and Kate wanted to offer an informal picture of the family together for Mother’s Day, with the princess making “minor adjustments”.
It was withdrawn with a “Kill” notice by picture agencies last night - and the UK’s PA news agency on Monday morning - because of suspicions it had been manipulated.