Prince Edward is widely regarded as the least controversial member of the sprawling and sometimes scandalous British royal family.
But according to Edward's royal biographer Ingrid Seward, the Earl of Wessex privately engaged in a war of words with his sisters-in-law Sarah, Duchess of York and Diana, Princess of Wales.
The Express UK reports that the youngest child of Queen Elizabeth and Prince Phillip "did not hold his sisters-in-law in high regard", allegedly taking cues from the Duke of Edinburgh who regarded the two women as being "substantially responsible for many of the difficulties that have beset the Royal Family and undermined their public standing".
According to Seward, Prince Edward believed Sarah and Diana had "let the side down" with their marital woes, open indiscretions and public airing of private family issues.
The Earl of Wessex, now 54, reportedly harboured a particular dislike for the outspoken Fergie who married his brother Prince Andrew in 1986.
Edward, who Seward refers to as "fiercely loyal", allegedly believed the Duchess of York was "making a fool of his brother" and blamed her for leaking sensitive information about the royal family to the press.
He specifically accused the mother of Princesses Beatrice and Eugenie of giving details of his romance with actress Sophie Rhys-Jones, now the Countess of Wessex, to Princess Diana's biographer Andrew Morton.
Morton later cleared Fergie of suspicion by admitting his source was a Palace employee.
The Queen - who continues to remain fond of her fiery daughter-in-law - was said to be so furious with her youngest son that she summoned him to explain to him "how unfair it was to accuse the Duchess of such disloyalty".
Of his relationship with the late Princess of Wales, Seward claims the Earl was "wary" of Diana and "sensed the trouble she would cause" Charles and the family from early in their courtship.