The King and Queen are mourning the loss of their close family friend, Captain Ian Farquhar, who died at the age of 78 on Wednesday.
The horseman and former equerry to the late Queen Mother reportedly passed away on Charles' Highgrove estate in Gloucestershire, where he had rented a farmhouse for many years, according to MailOnline's Richard Eden.
Camilla's former husband, Andrew Parker Bowles, described him as as "a real countryman, a very good officer, a brave amateur rider, a hard-riding polo player and an excellent public speaker".
Mr Farquhar was educated at Ludgrove and Eton and served in the UK, Middle East, Aden and the Far East with the Queen's Own Hussars. He became the Queen Mother's equerry in 1971, staying in the post for two years.
He became joint-master and huntsman of the Duke of Beaufort's Hunt in 1985, only retiring as a huntsman in 2010 and remaining a joint-master until 2019.
In 2023, Mr Farquhar published his memoir The Way It Was about his life and work. He married Pamela J Chafer in 1972 and the couple shared three daughters.
Their youngest daughter, Rose Farquhar, reportedly dated Prince William in 2000 after he completed his A-Levels at Eton.
Rose was a guest at Prince Harry and Meghan Markle's royal wedding in 2018, and in turn, William attended Rose's nuptials to George Gemmell in Gloucestershire in December 2022.
The news of Mr Farquhar's death comes at a difficult time for the royal family amid the King's cancer treatment and the Princess of Wales's recovery from abdominal surgery.
The Queen is taking a short break from her duties but will return next week to lead the royals with Prince William at the Commonwealth Day service at Westminster Abbey on Monday 11 March.