Prince Philip, Britain’s longest-serving consort, returned to Windsor Castle Tuesday after he was hospitalized for an infection and undergoing a heart procedure on Feb 16. The past four weeks were the longest ever hospital stay of the Duke of Edinburgh.

Philip, 99, the husband of Queen Elizabeth II, had been hospitalized since being admitted to the private King Edward VII’s Hospital in London on Feb. 16, where he was treated for an infection. He was later transferred to a specialized cardiac care hospital, St. Bartholomew’s, for a short stay, before returning to King Edward VII’s. Photographers standing outside the door of the private hospital captured his departure in the back of a black car.

Buckingham Palace has not yet commented on the matter. Philip’s illness is not believed to be related to the coronavirus. Both Philip and Elizabeth received COVID-19 vaccinations in January and chose to publicize the matter to encourage others to also take the vaccine.

Philip, also known as the Duke of Edinburgh, retired in 2017 and rarely appears in public. Before his hospitalization, he had been isolating at Windsor Castle, west of London, with the queen. His illness comes as the royal family has been rocked by an interview with Meghan, Duchess of Sussex, and Prince Harry. In the explosive broadcast, Meghan, who is biracial, said the palace had failed to help her when she had suicidal thoughts and that an unidentified member of the royal family had raised "concerns" about the color of her baby’s skin when she was pregnant with her son, Archie. The interview, conducted by Oprah Winfrey, divided people around the world.

While many say the allegations demonstrate the need for change inside a palace that hasn’t kept pace with the #MeToo and Black Lives Matter movements, others have criticized Harry and Meghan for dropping their bombshell while Philip was hospitalized. The longest-serving royal consort in British history, Philip married the then-Princess Elizabeth in 1947. He and the queen have four children, eight grandchildren and nine great-grandchildren.