Taking to social media site X, the Earl shared a screenshot of the list as he expressed his gratitude, writing: “Thank you for all those who have been buying A Very Private School – keeping it in The Times Top 10 in hardback non-fiction for the fourth week in a row. I’m very grateful indeed.”

The thrilling announcement marked the culmination of a hectic weekend for Princess Diana’s sole brother, who revealed significant family news the day before. The father of seven took to Instagram to share an endearing video featuring a litter of Labrador puppies enthusiastically jumping towards the camera and wagging their tails.

Charles captioned it: “One of these darlings is joining me for a new life at Althorp in a few days. Can’t Wait!” He was deluged with comments, including more than one who understandably suggested that he should “take two”. 

At 59 years old, Charles Spencer’s youngest child is his daughter Charlotte Diana, whom he shares with his wife, Lady Karen Spencer. Recently, Charles offered a rare glimpse of his daughter during their annual Easter egg hunt.

The youngster could be seen riding up to a gatepost on a white pony in front of the family home, Althorp House, and collecting an egg before circling to the other side and picking up another egg. 

Dressed in pyjamas with riding boots, a black coat and matching hat, Charlotte looked back to the camera and joked: “I’m glad I didn’t go bareback.”

Revealing how protective he is, Charles recently explained: “I have an 11-year-old, I have many children, and my youngest one I do the school run with her in the morning and it’s a hoot, she’s really funny and fun. 

“She’s quite bored of me asking, ‘Are there any strange teachers at school?’ She sort of rolls her eyes and says, ‘For goodness’ sake, we’ve been through this,’ but I will always be on guard.” 

Charles’ concerns for his daughter’s wellbeing are the result of his own experiences at boarding school. In his memoir, the Earl writes that he was sexually abused by a teacher. 

In an extract from his book that was serialised in the Mail on Sunday, he wrote: “There seemed to be an unofficial hierarchy among her prey… she chose one boy each term to share her bed and would use him for intercourse. Her control over mesmerised boys was total, for we were starved of feminine warmth and desperate for attention and affection.” 

In another extract from the book, Charles claimed he was beaten with the spikes of a cricket boot by the school’s Latin master. 

He described reliving his experiences at the school as “an absolutely hellish experience”, writing: “I’ve frequently witnessed deep pain, still flickering in the eyes of my Maidwell contemporaries. Many of us left Maidwell with demons sewn into the seams of our souls.” 

In response to the claims in the book, Maidwell Hall said it was “sorry” about the experiences reported by Earl Spencer and some of his contemporaries.