The image was taken by Princess Kate in 2024, according to the social media post.

Earlier, William released a picture of himself and his father, King Charles, playing football to mark Father’s Day.

In the photograph, the young prince smiles as he and the future monarch stand in a garden.

The royal youngster is pictured wearing dungarees and a striped shirt, while Charles looks relaxed in a double-breasted suit jacket.

The picture of the two future kings was taken on 12 June, 1984 in the gardens of Kensington Palace.

Later that same year William would gain a younger brother, with the Duke of Sussex born in September.

As well as marking Father’s Day, the football-themed image is perhaps a nod to England’s opening match in the Euros, which takes place on Sunday night.

The Royal Family’s account on X also posted archive footage of the King as a baby with his own father, the late Prince Philip.