Katharine, the Duchess of Kent, has died at the age of 92, the King and Queen said. She died peacefully at home late on Thursday night, surrounded by her close family. She was the wife of the late Queen’s cousin, the Duke of Kent, and is survived by three children — George, Earl of St Andrews; Lady Helen Windsor; and Lord Nicholas Windsor.

The Palace said union flags were lowered to half-mast at Buckingham Palace and other royal residences where the monarch is not in residence as a mark of respect. A formal notice confirming the duchess’s death was placed on the railings at Buckingham Palace, and the King has approved a period of Royal Mourning until and including the day of her funeral, which is expected to be held in about a week. In a message on Kensington Palace’s official social media accounts, William and Kate wrote: “Our thoughts today are with the Duke of Kent and his family, particularly George, Helen and Nicholas. The duchess worked tirelessly to help others and supported many causes, including through her love of music. She will be a much missed member of the family.” The post was signed “W & C”.