Prince William shares unseen photo of Princess Diana in UK Mother’s Day tribute

The royal family is honoring mothers this U.K. Mother's Day, including a never-before-seen photo of Princess Diana and young Prince William.

It’s Mother’s Day in the United Kingdom, and Prince William is remembering the late Princess Diana in a new social media tribute.

The never-before-seen photo, posted to the official account of the Prince and Princess of Wales, features a young Princess Diana with a 2-year-old William in a field of flowers in 1984, according to the BBC.

"Remembering my mother, today and every day. Thinking of all those who are remembering someone they love today. Happy Mother’s Day. W," William wrote on Instagram. Princess Diana died at 36 in 1997 in a fatal car crash and would have turned 65 in July of this year. At the time of her death, Prince William was 15 and Prince Harry was 12.

Both sons have been open about their grief after losing their mother. In 2017, William said he frequently tells his children about Diana and that he knows she would "be a lovely grandmother." The princes continue her legacy at the Diana Legacy Awards Ceremony, an annual award that honors young people for "inspirational work."

Queen Camilla and King Charles III also posted photos of their relatives to social media under their official royal family page, including Queen Elizabeth II and Queen Camilla’s late mother, Rosalind Shand. One photo shows the late Queen sitting with a young King Charles and his sister Anne, the Princess Royal. The Queen’s corgi is in the background.