London: Princess Diana’s hand-written letters , including one unveiling how her son Prince Harry was “constantly in trouble”, sold for £15,100 at auction in London, exceeding the £2,300-£3,600 estimate.

The former Princess of Wales had sent the letters to late Cyril Dickman, who served as a head steward at Buckingham Palace for more than 50 years.

Dickman died aged 85 in 2012 and the letters were uncovered by his grandson who presented them for auction .

In them she wrote about how William “swamped” his new baby brother with “an endless supply of hugs and kisses” and how “naughty” Harry was constantly getting into trouble at school.

 “The boys are well and enjoying boarding school although Harry is constantly in trouble!” the princess describes about trouble, in one letter, dated October 17, 1992. “We are off to Korea in November so a good place to do Christmas Shopping!” she adds.

A letter where Diana told about Prince William’s adoration for younger brother Harry, was sold for £3,200.

The entire Dickman collection, which also included letters from Queen Elizabeth II and Prince Charles, contained around 40 lots which were estimated to fetch around 13,000 pounds .

But they went under the hammer for around 55,000 pounds .

The Diana letters, split into six lots, were expected to fetch around 3,600 pounds , but went for a total of 14,900 pounds .

In one personal letter dated 20 September 1984, Diana writes: “William adores his little brother and spends the entire time swamping Harry with an endless supply of hugs and kisses, hardly letting the parents near!