Before they became the Duke and Duchess of Cambridge, they started dating while studying at St Andrews and it was eight years before William got down on one knee.
To help Kate transition from university student to royal, William reportedly set up a hotline for Kate so that she felt supported as she adapted to life in the public eye.
However, according to journalist and author Catherine Mayer, there was one thing that Kate ‘didn’t know’ before she married the prince.
In the 2017 ITV documentary Kate: The Making of a Modern Queen, Mayer said: ‘The one thing I suppose she may not have known, and will now know, is just how peculiar royal life is.
‘It’s the strangest place I have ever spent time ‒ the palace.
‘Just that sense of never ever really being alone and the palaces are sort of strange old buildings that are all about actually being built for show, for people to look inwards, and so they’re really not about comfort, they’re really not about family life.’
Mayer also said that Kate will only now understand the proper etiquette and royal protocol involved in their daily lives, but revealed that she was ready to take on the role following her brief split from William in 2007.
During their engagement interview in 2010, Kate admitted that the break had upset her but ultimately made her stronger. Royal experts believe that the break up was a ‘testing period’ and made them realise they were destined to be together.
Mayer said: ‘I don’t think there’s anything at this stage that I could teach Kate about being a member of the Royal Family, because she clearly took to it very quickly.
‘But she also had this very interesting period in her relationship with the prince where they split up and got back together again, which was very clearly a testing period, a proving period, something where she had already been through the baptism of fire in terms of what it meant for destroying any chance of a private life she would ever had, and she went into it in that sense with her eyes open.’
The couple have gone from strength to strength over the years, and – as they say – the rest is history!