Prince Harry was "constantly in trouble" when he was at school.
The 32-year-old royal has been described as a mischievous child by his late mother Princess Diana - who tragically died in a car crash in Paris, France, in 1997 aged 36 - in hand written letters which have been released and are set to go on auction.
The letter, which has been obtained by BBC News, reads: "[Harry and William] are well and enjoying boarding school a lot, although Harry is constantly in trouble."
Whilst the flame-haired hunk has been credited with a playful sentiment, his older brother the Duke of Cambridge, 34, was more of a soft and gentle child, as he used to "swamp" his younger sibling with love when he was younger.
In a card to the former Buckingham Palace steward Cyril Dickman, which was dated in 1984, it said: "William adores his little brother and spends the entire time swamping Harry with an endless supply of hugs and kisses."
And Diana joked Prince Williams overt affection to Harry made it difficult for her and her former partner Prince of Wales go near him.
She added: "[William's] hardly letting the parents near."
And the golden-haired beauty has revealed the birth of her second child "totally overwhelmed" her and Prince Charles, who split from Diana in 1996.
The letter continued: "The reaction to one tiny person's birth has totally overwhelmed us and I can hardly breathe for the mass of flowers that are arriving here!"
The letter is reportedly set to sell in the sale from anything between £300 and £900.