Princess Diana and Prince Charles
Princess Diana reportedly made life difficult for Prince Charles. The Princess of Wales Diana, Princess of Wales attend a centenary service for the Royal College Of Music on Feb. 28, 1982 at Westminster Abbey, London. Fox Photos/Hulton Archive/Getty Images

Although Princess Diana and Prince Charles divorced in 1996, the years leading up to their split was reportedly riddled with insults and frequent arguments that eventually ruined the couple’s marriage.

According to “Prince Charles: The Passions and Paradoxes of an Improbable Life,” author Sally Bedell Smith claimed Diana’s “erratic behavior weighed heavily on Charles” throughout their marriage.

In the book, Bedell Smith revealed Pamela Hicks, the Prince of Wales’ cousin, accused Diana of attacking Charles following a tense argument. “Diana would hit him over the head and keep on with the row while he was praying,” she claimed.

The author went on to suggest Princess Diana’s taunts also included telling Prince Charles “you’ll never be king” and teasing that he looked “ridiculous in all those medals” when he wore his uniform.

The Princess of Wales reportedly made Charles even more miserable by forcing him to cut off his close friends, who she suspected was helping him cover up his infidelity, and getting rid of his beloved Labrador.

Although Charles went on to have an affair with Camilla Parker Bowles and eventually married his mistress, insiders claimed he was devastated by Princess Diana’s tragic death a year after their divorce.