They will lead tributes for the late Queen, a trip which will form part of their plans to return to work after their summer break.
Prince William will pay homage to his beloved grandmother, honouring her life and legacy, but is also keen to show the Firm are “looking to the future”.
He will not address the congregation directly.
A source said: “It will be an emotional day for all the Royal Family, as well as many people across Britain, recognising this date.
“But of course for others, it will be just another day and life goes on.”
