LONDON: Queen Elizabeth the Queen Mother thought it was “utterly abhorrent” when Prince Charles and princess Diana went public on their marriage failings, according to her official biography released today.

The biography also revealed that the queen mother, who died in March 2002 aged 101, suffered from colon cancer. The royal matriarch regretted her grandson’s decision to admit adultery during a 1994 television interview, said the biographer William Shawcross, who was chosen by Queen Elizabeth II to write an account of her mother’s life. The queen mother, widow of king George VI, was also upset that Diana collaborated privately with Andrew Morton on his book that exposed her life within the royal family. In a later BBC interview Diana famously admitted that “there were three of us in this marriage, so it was a bit crowded” — a reference to Charles’ relationship with Camilla Parker-Bowles, whom Charles has since married. During a taped 1990s interview which was kept in a royal archive, the Queen Mother said: “It’s always a mistake to talk about your marriage.” Married in 1981, heir to the throne Charles and his first wife Diana separated in 1992 and divorced in 1996.

The princess’s collaboration with Motion was “deeply shocking” to the queen mother, the last empress of India, who felt “the washing of dirty linen in public was utterly abhorrent”, according to Shawcross.

He added: “She did not cast the princess aside at this time but she gave her grandson as much emotional support as she could.” The biography also revealed that the queen mother underwent a 90-minute operation to remove a tumour in 1966. At the time, a statement said she underwent abdominal surgery to relieve a partial obstruction. She spent two weeks in hospital and cancelled all engagements for the next three months. Shawcross, who interviewed the queen’s former physician Richard Thompson, also quashed rumours that she was fitted with a colostomy bag. “Many people who had to endure that operation themselves derived comfort from the belief that even someone with as active a life as queen Elizabeth could manage so well after such a difficult procedure,” he wrote.