Royals British Royal Family Prince William Pulls Out of Memorial Service for Godfather Due to Personal Reasons, Palace Says A palace source tells PEOPLE that Kate Middleton "continues to be doing well" amid her recovery from abdominal surgery By Simon Perry Simon Perry Simon Perry is a writer and correspondent at PEOPLE. He has more than 25 years’ experience at PEOPLE covering the royals, human interest and celebrity. People Editorial Guidelines Updated on February 27, 2024 12:32PM EST Prince William dropped out of a ceremony to honor his godfather King Constantine of Greece due to a personal matter, Kensington Palace says. The Prince of Wales, 41, pulled out of the service of Thanksgiving at St. George's Chapel in Windsor Castle on Tuesday. The personal matter is not related to the health of his father, King Charles, who was recently diagnosed with cancer, PEOPLE understands. Prince William, who was set to do a reading at the service according to the order of service, was due to attend without his wife Kate Middleton, 42, who is recovering from her recent abdominal surgery at home in Adelaide Cottage on the Windsor estate. While the palace didn't indicate whether William's absence was due to Kate's recovery, a palace source tells PEOPLE she "continues to be doing well." Prince William in London on September 13, 2023. JUSTIN TALLIS/POOL/AFP via Getty Images Constantine, who was the last King of Greece, died in January 2023 at age 82 and among the congregation for the service was King Constantine's widow, Queen Anne-Marie, and their son Crown Prince Pavlos with his wife, Crown Princess Marie-Chantal. Prince William informed the late King's family he was unable to attend ahead of the event. Prince William has been helping to care for his wife Kate Middleton at home in Adelaide Cottage. Max Mumby/Indigo/Getty Prince William Apologizes for Kate Middleton Missing Awards amid Surgery Recovery: 'She Does Love the BAFTAs' Queen Camilla formally led the British royal family, stepping in for her husband, King Charles, who is undergoing cancer treatment and has canceled most public-facing duties. She was joined by family and friends, as well as royals from around the world, at the service. Queen Camilla arrives at the thanksgiving service on Tuesday, February 27, 2024. ANDREW MATTHEWS/POOL/AFP via Getty Images Among the members of the British royal family walking into St. George's Chapel on Tuesday morning were Prince Andrew and his ex-wife Sarah Ferguson, the Duchess of York, who live under the same roof at Royal Lodge on the Windsor estate. Although Prince Andrew stepped back from his royal role in 2019 and was stripped of his military titles and patronages by Queen Elizabeth in 2022 due to his ties to convicted sex offender Jeffrey Epstein, he has continued to attend family-centric events such as Christmas. The big turnout of royals also included their eldest daughter Princess Beatrice and her husband Edoardo Mapelli Mozzi. Prince Andrew and Sarah Ferguson, the Duke and Duchess of York arrive at the service at St. Geroge's Chapel, Windsor Castle. CHRIS JACKSON/POOL/AFP via Getty Images Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! King Charles' sister, Princess Anne, also attended with her husband Sir Timothy Laurence, her daughter Zara Tindall and her son-in-law former rugby player Mike Tindall. The guests at the Windsor Castle service also included Princess Alexandra, the Duke and Duchess of Gloucester, Prince and Princess Michael of Kent, the Duke of Kent and Princess Margaret's daughter Lady Sarah Chatto. Outside the British royal family, King Felipe and Queen Letizia of Spain as well as former King Juan Carlos and Queen Sofia of Spain, Princess Benedikte of Denmark, Queen Noor of Jordan and Prince Constantijn of the Netherlands. Zara and Mike Tindall are joined by Princess Anne, and Princess Beatrice for the service at Windsor. Chris Jackson/Getty Images The links between the British and Greek royal families are strong, and Constantine was a close friend of both King Charles and his late mother, Queen Elizabeth. Her husband, Prince Philip, was born in Crete and was a first cousin of King Constantine's father, King Paul I. Prince William is himself godfather to one of Prince Pavlos' children. Constantine acceded to the throne at the age of 23 in 1964, reported the Associated Press. By then, he was already an Olympic gold medalist in sailing. The Greek monarchy was abolished in 1973, after which the last King lived in exile in Britain. Though he returned for some short visits, including in 2004 when Constantine returned to Greece temporarily during the Athens Olympic Games as a member of the International Olympic Committee, he was only able to live in his home country again in 2013. The late King Constantine of Greece. Jeff Overs/BBC News & Current Affairs via Getty Meet the Greek Royals: All About the Modern Princes and Princesses of the Former Monarchy After suffering from chronic heart and mobility problems, his condition worsened and he was hospitalized last January, according to Reuters. He died in Athens, the city of his birth, on January 10, 2023. Prince William did not attend King Constantine's funeral last year. Instead, he asked his relative Lady Gabriella Windsor to represent him. It was a poignant choice as Lady Gabriella is the daughter of Prince Michael of Kent, a first cousin to the late Queen Elizabeth, to whom Constantine was a close friend. Gabriella and William also share another link: Constantine was a godfather to them both. At the funeral, Princess Anne stood in for her brother King Charles at the solemn ceremony in Athens. Queen Anne Marie of Greece and Crown Prince Pavlos of Greece attend the funeral of Former King Constantine II of Greece. Patrick van Katwijk/Getty Images It is customary for senior royals in Britain to send relatives or close friends and aides to funerals on their behalf. The late Queen Elizabeth only rarely attended funerals. King Charles appears to be following the same custom and sending a family member instead. Other royals from around the world in attendance at the funeral included Prince Albert of Monaco, King Felipe and Queen Letizia of Spain, Queen Margrethe of Denmark (who was the late monarch's sister-in-law), King Philippe and Queen Mathilde of Belgium, King Willem-Alexander and Queen Maxima of the Netherlands and Crown Prince Haakon of Norway and Crown Princess Mette-Marit of Norway.