The previously unseen image, taken from the family's private collection, shows Diana with a two-year-old William in 1984, sitting in a field full of wildflowers at the family's main home of Highgrove, Gloucestershire. Posting on Instagram, William wrote: "Remembering my mother, today and every day. Thinking of all those who are remembering someone they love today. Happy Mother's Day. W"

Diana, who died aged 36 following a car crash in 1997, would have turned 65 on 1 July this year. Her sons Prince William and Prince Harry were aged 15 and 12 respectively at the time of her death. Both brothers have over the years spoken openly about the traumatic impacts of losing their mother at a young age. The Royal Family's official X account also shared a Mother's Day message accompanied by a selection of photos. The caption read: "Wishing Mothers everywhere, and those who might be missing their Mums today, a restful Mothering Sunday".

A black and white photograph taken in 1953, shows the late Queen sitting on a bench with the King and his sister Anne, now the Princess Royal, at Balmoral, Scotland. The Queen's corgi, Sue, can be seen in the background. Notably absent are the King's younger brothers - Andrew Mountbatten-Windsor and Prince Edward, now the Duke of Edinburgh - who were not born at the time. Other images shared include a black and white photo the late Queen Elizabeth II with the Queen Mother, as well as a image of Camilla with her late mother Rosalind Shand. (BBC/ @KensingtonRoyal)