(CNN) – Prince William will miss a memorial service for the late King Constantine of Greece for personal reasons, a royal source told CNN.
The 41-year-old Prince of Wales was due to attend the memorial service at Windsor Castle on Tuesday.
The source did not elaborate on the last-minute change in plans, but added that William's wife, the Princess of Wales, “continues to do well” as she recovers from abdominal surgery in January.
The same source added that William called the family to let them know he couldn't attend.
Kate has remained out of the public eye as she continues to recover at home and is not expected to return to royal duties until after Easter.
Also King Charles III. is off duty as he continues treatment for an unknown type of cancer. The 75-year-old monarch recently revealed that the numerous messages of support he has received since his cancer diagnosis brought him to tears.
Another royal source told CNN that there is no connection between the Prince of Wales's personal matter and the king's health.
Queen Camilla leads the family at a gathering in honor of the last Greek monarch at St George's Chapel.
Constantine II of Greece, second cousin of King Charles III, died in January last year at the age of 82.
Charles and Constantine maintained a close relationship, and the British royals even named his cousin godfather to their first-born son, William.
After a military coup in 1967, Constantine and his family fled to Rome and the military regime appointed a regent in his place.
The Greek monarchy was abolished on June 1, 1973, when the military regime proclaimed the country a republic, a decision supported by a subsequent referendum. Constantine accepted abolition after an elected civilian government held another referendum in 1974.