Earl Charles Spencer delighted fans at the weekend when he took a trip down memory lane and unearthed a pair of historic photographs.
Taking to Instagram on Sunday, Prince William and Prince Harry's uncle uploaded two sepia pictures from between 1940 and 1941.
One showed Charles's grandfather posing outside Althorp whilst rocking military uniform and a bristling moustache. The second, meanwhile, showed his father in his youth similarly dressed in army gear from his time in the Corps.
In his caption, the historian and podcast host explained: "Two photographs from 1940 or 1941: my grandfather and father, on a war footing in the front courtyard of @althorphouse.
"My grandfather had fought as a cavalry officer, and had been wounded, in the First World War. He had an honorary army rank at the time of this portrait with his dog. That’s my grandmother in the distance."
He continued: "My father was in the Corps at @eton.college - he became an officer cadet there, before serving with the Royal Scots Greys in Normandy."
In the comments section, Charles' fans couldn't help but notice the striking similarity between Charles's father and the eldest son of the Prince and Princess of Wales, Prince George.
Reflecting on the family resemblance, one follower noted: "Prince George is the spitting image of your father," while a second penned: "I see his father in William also."
A third wrote: "I see you and Diana in your father's face! Wonderful photos, thanks, for sharing," and a fourth chimed in: "Such lovely photos of your father & grandfather! You resemble your father so much!"
Charles inherited his family's ancestral home, Althorp House, in 1992 aged 27. The stately home, where he used to live with his late sister Princess Diana, boasts 90 rooms and sits on 13,000 acres.
It's also home to Diana's final resting place which is located on the property's ornamental lake. During a recent appearance on Good Morning Britain, the 60-year-old revealed how one of Diana's childhood friends recently paid a visit to her gravesite.
"I go pretty much every day," he told Susanna Reid and Richard Madeley. "Last week one of her closest childhood friends came and was on the island. And that was so nice."
Diana's resting place is only accessible via boat and is off-limits to the public. There used to be a bridge in place so that visitors could access the island, but it was later removed for security reasons.
Writing in his memoir Spare, Prince Harry explained: "The bridge had been removed, to give my mother privacy, to keep intruders away."