The Earl’s relationship with the Countess of Spencer broke down amid the strain of writing his harrowing memoir detailing the physical and sexual abuse he suffered at boarding school, it is understood.

The couple announced their pending divorce to staff at Althorp, the Spencer family estate in Northamptonshire, in March.

‘It is immensely sad,’ Earl Spencer told the MoS last night.

‘I just want to devote myself to all my children, and to my grandchildren, and I wish Karen every happiness in the future.’

Earl Spencer and Karen Gordon, a Canadian philanthropist, married in June 2011 within the grounds of Althorp, where the Earl’s older sister Princess Diana is buried. The couple had met the previous year on a blind date at a restaurant in Los Angeles.

Earl Spencer and Karen Gordon, a Canadian philanthropist, married in June 2011 within the grounds of Althorp

Speaking to The Sunday Times in 2020, the Earl said: ‘Karen and I both appreciate what the other does and look after what we have. Neither of us has found happiness like this before.’

His wife was notable by her absence at events held at Althorp and Spencer House in London in mid-March to launch the Earl’s book, A Very Private School.

Charles Spencer told the MoS that the five years of work on his memoir has deeply affected him and led to him undergoing residential treatment for trauma late last year.

He is understood to have been particularly traumatised by his discovery of his 1976 schoolboy diary, in which the assistant matron, who he alleges sexually abused him, had written a long-forgotten message.

The diary was discovered on the high shelf of a room at Althorp that was being refurbished after he completed the main body of his book.

Earl Spencer wrote he was ‘rocked’ by the discovery and described how the woman, who The Mail on Sunday is today identifying as 67-year-old grandmother Sally Jane Carr, has simply written ‘Me’ along with her address and telephone number.

‘There is something about the word, ‘Me’, that strikes me now as not only wildly inappropriate, but intensely intimate – and, of course, slyly anonymous.’

The Earl’s memoir also revealed the trauma of his mother leaving him and Diana when he was three-years-old and how being brought up by a succession of nannies also impacted him.

Charles married his second wife Caroline Freud in 2001 but the pair got a divorce in 2009

Charles and his first wife Victoria Lockwood got married in 1989 and then divorced in 1997

During an interview with the Therapy Works podcast in March, Earl Spencer said that being abused as a child had a profound impact on his choice of romantic partners in adulthood. He said he was left susceptible to women who were incapable of loving him.

‘I think I went for good-looking people who weren’t really into love,’ he said.

‘I’m having a good look at myself and everything around me and I think I would be a lot easier to live with now than I ever have been in the past.’

Earl Spencer, meanwhile, has recently become close to Norwegian archaeologist Cat Jarman. The pair, along with the Rev Richard Coles, host The Rabbit Hole Detectives, a history podcast.

Dr Jarman, who is separated from her husband, has appeared on BBC Two’s Digging for Britain and was last month awarded ‘Nordic Person of the Year’ by the Confederation of Scandinavian Societies.

She has also been helping Earl Spencer unearth a Roman villa in the grounds of Althorp. Friends say they look very happy together but that it is early days.

Karen’s first husband was millionaire Hollywood producer Mark Gordon, known for his work on Saving Private Ryan and The Day After Tomorrow, who she met while working on the front desk of the Four Seasons in Toronto in 1994.

The couple married three years later but split in 2003 and Karen reportedly received a $1.3 million settlement. She was later linked to billionaire George Soros.