The 75-year-old monarch, who will be at the Windsor Castle service with Queen Camilla, has recently stepped back from major public duties while receiving treatment.

But he is continuing to carry out low-key official duties behind palace walls, including weekly meetings with Prime Minister Rishi Sunak.

Last Thursday, he spoke during the Royal Maundy Service in Worcester, in a pre-recorded audio message.

He stressed the importance of acts of friendship "especially in a time of need", in words that were interpreted as reflecting on the nation's response to his health challenges.

He said earlier this month he had been reduced to tears by the messages and cards of support he had received.

The Easter service at St George's Chapel comes just over a week after his daughter-in-law Kate released an emotional video message disclosing she has started preventative chemotherapy for cancer.

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She, Prince William, and their three children - George, 10, Charlotte, eight, and five-year-old Louis - will not be at today's service.

The family are spending the Easter holidays together as they adjust to the Princess of Wales's diagnosis, which was discovered in post-operative tests after major abdominal surgery in January.

William's younger brother Harry and his family will also not be there, as they remain settled in the US.

Prince Andrew and his daughters are expected to attend, as are the Princess Royal, and the Duke and Duchess of Edinburgh - Edward and Sophie.