According to the sensational claims, Camilla is even said to have asked Prince Charles to convince William to end things with Kate.
After six years of being together, Kate and William briefly broke up in 2007 and the book claims Camilla at the time described the separation as 'wise.'
In an interview with the BBC following the announcement of their engagement, William said: 'We did split up for a bit. We were both very young, we were both at university, we were both finding ourselves as such, being different characters.
'We were both trying to find our own way with a bit of space, we were growing up and then it worked out for the better.'
A Clarence House spokesman said they would not comment on the book’s claims.
Related: Prince Charles 'chucks' Camilla Parker-Bowles out of Kensington Palace