Earl Spencer recently melted hearts with a very rare glimpse of his daughter Lady Lara Spencer as she supported him at the launch party for his memoir, A Very Private School.
Father-of-seven Charles is also a hands-on dad to his youngest child, Charlotte Diana, who he shares with his third wife Karen.
And as he revealed in a recent interview, he's very protective of his daughter, for understandable reasons.
Speaking to his late sister Princess Diana's close friend Julia Samuel on an episode of her podcast Therapy Works, the Earl opened up about his experience of physical and sexual abuse at Maidwell Hall Prep School, the boarding school he attended between the ages of eight and 13.
He revealed that the experience had ensured that he never forced his own children to board and shared how he tries to keep his youngest daughter safe.
The doting dad commented: "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 lives with his family at the Spencer family estate where he and the late Princess of Wales grew up and where Diana was laid to rest. Earlier this month, the 59-year-old uploaded a scenic video of the ornamental lake which is home to Princess Diana's tranquil gravesite.
The majestic Oval Lake looked breathtaking in the spring sunshine as the sunlight rippled across the water. Perfectly manicured grass hugged the water's edge and a cacophony of birdsong pierced the silence.
"Such an exquisite morning at @althorphouse today - birdsong providing the high notes, with woodpeckers on percussion," Charles wrote in his caption.
During a brave interview ahead of the launch of his book, the Earl spoke about his relationship with his sister, with whom he was very close, and revealed one of Princess Diana's biggest fears.
Charles opened up about how his late sister cared for him after their mother left the family home and explained that one of her great fears was the dark. Charles said: "Diana looked after me because she was nearly three years older than me.
"She said that the worst part was hearing me cry down the hall because she was terrified of the dark and couldn't come to me."
The Earl had a very close bond with his sister and also explained how he felt it was his duty to keep Diana grounded following her relationship with Prince Charles.
He said: "I remember going to a dinner soon after she'd become what she became, given by sort of friends in a private room in a restaurant in Fulham. I remember thinking, 'Crikey, they're all sucking up to her like crazy.' I realised that my job was to be absolutely solid as a brother and just remain the same."