According to Royal author Katie Nicholl, after dating since 2003, by the end of March 2007, it seemed as though “their love affair had run its course".
Writing in her 2010 book William and Harry, she said Kate had delivered an ultimatum when William was pictured partying and flirting with other girls in London and near his military training base at Bovington.
However, the strategy “backfired” and “William told her that they should have a break", which was when the couple split for a few months.
“Haunted by the spectre of the past, there were real fears at the Palace that Kate would become the next Camilla,” she wrote.
This was when comparisons were drawn between the choices William was making, and how his father's early relationship with Camilla had played out in the 1970s.
Prince Charles and Camilla's relationship came to an end when Charles had been forced to call it off in January 1973 when he went on deployment with the Royal Navy.
Charles was then reportedly heartbroken when Camilla became engaged to her first husband, Andrew Parker Bowles, later that year.
Meanwhile Charles went on to marry Lady Diana, who became, Diana, Princess of Wales on their 1981 wedding day.
Charles and Camilla's love for each other famously didn't wane, which caused problems for the Prince in his marriage to Diana.
Something Diana was acutely aware of, as she told the BBC in 1995: “Well, there were three of us in this marriage, so it was a bit crowded.”
Diana and Charles split and were finally divorced in 1996, just a year before her tragic death.
Camilla and Andrew had also called time on their marriage in 1995, and the Duke and Duchess of Cornwall eventually married each other in 2005.
While William and Kate were married in a lavish ceremony in 2011.