The Prince of Wales was scheduled to attend a memorial service for King Constantine of Greece -who died in January 2023, aged 82- at Windsor Castle on Tuesday (27.02.24), but he made a late withdrawal from the event for personal reasons.
In his absence, Queen Camilla lead members of the royal family at the service.
The news of William's withdrawal was announced less than an hour before the start of the event at St George's Chapel.
Kensington Palace has not offered a specific reason for William's absence. However, the 41-year-old prince called the Greek royal family who are attending the service to inform them of his absence.
King Constantine was William's godfather, as well as being the first cousin once removed of the Duke of Edinburgh.
Meanwhile, in January, the Princess of Wales underwent abdominal surgery.
Although the surgery was a success, the princess is unlikely to return to public duties until after Easter.
Kensington Palace said in a statement at the time: "The Princess of Wales appreciates the interest this statement will generate. She hopes that the public will understand her desire to maintain as much normality for her children as possible; and her wish that her personal medical information remains private.
"Kensington Palace will, therefore, only provide updates on Her Royal Highness' progress when there is significant new information to share."
Elsewhere, King Charles was recently diagnosed with "a form of cancer" after he underwent surgery on an enlarged prostate.
In a statement released on February 5, Buckingham Palace said: "During The King's recent hospital procedure for benign prostate enlargement, a separate issue of concern was noted. Subsequent diagnostic tests have identified a form of cancer.
"His Majesty has today commenced a schedule of regular treatments, during which time he has been advised by doctors to postpone public-facing duties. Throughout this period, His Majesty will continue to undertake State business and official paperwork as usual.
"The King is grateful to his medical team for their swift intervention, which was made possible thanks to his recent hospital procedure. He remains wholly positive about his treatment and looks forward to returning to full public duty as soon as possible."