Britain’s Prince William has pulled out of attending a memorial service for the late King Constantine of Greece at Windsor Castle due to a personal matter.

Kensington Palace would not elaborate further but said his wife, Kate, who is recovering from abdominal surgery, continues to be doing well.

William, who was due to deliver a reading, called the Greek royal family who are attending the service in St George’s Chapel to let them know he was unable to attend.

Constantine II of Greece, who died in January last year, was William’s godfather.

Kate is away from official royal engagements until after Easter following major surgery in January.

Britain’s King Charles is also missing the service as he continues treatment for an undisclosed form of cancer.

Charles was close to his second cousin, the former Greek monarch.

Constantine was a first cousin once removed and sailing partner of the late Prince Phillip, and died at the age of 82 in January last year, decades after being toppled from the throne in a military coup.