Catherine, Duchess of Cambridge visits the Hampton Court Flower Festival with children from Hampton Hill junior school at Hampton Court Palace on July 1, 2019 in London, England. The Duchess visits her Back to Nature Garden at Hampton Court Palace Garden Festival that she co designed with Andrée Davies and Adam White (Photo by Heathcliff O\'Malley - WPA Pool/Getty Images)

Catherine, Duchess of Cambridge visits the Hampton Court Flower Festival with children from Hampton Hill junior school at Hampton Court Palace on July 1, 2019 in London, England. The Duchess visits her Back to Nature Garden at Hampton Court Palace Garden Festival that she co designed with Andrée Davies and Adam White (Photo by Heathcliff O'Malley - WPA Pool/Getty Images)Image: Getty Images

As Prince William's wife, Kate Middleton's title as Duchess of Cambridge will automatically change when Queen Elizbabeth II either dies or steps down and Prince Charles becomes king 

Prince William is second in line to the throne, and as rumours circulate that Queen Elizabeth is expected to hand over the crown to her son Prince Charles within the next two years, we can't help but wonder what does this mean for Kate Middleton?

Read more: Kate Is Now A Dame Grand Cross of the Royal Victorian Order. What's that?

ueen Elizabeth II is shwon around 'Back to Nature' by Prince William and Catherine, Duchess of Cambridge at the RHS Chelsea Flower Show 2019 press day at Chelsea Flower Show on May 20, 2019 in London, England. (Photo by Geoff Pugh - WPA Pool/Getty Images)

ueen Elizabeth II is shwon around 'Back to Nature' by Prince William and Catherine, Duchess of Cambridge at the RHS Chelsea Flower Show 2019 press day at Chelsea Flower Show on May 20, 2019 in London, England. (Photo by Geoff Pugh - WPA Pool/Getty Images)

Currently known as the Duchess of Cambridge, when William becomes next in line to the throne, his title will automatically change to Prince of Wales, the title historically held by those first in line. In fact, this title was offically granted to Prince Charles at his investiture 50 years ago, and he's the 21st man to hold the title.

When Charles married Diana Spencer in 1981, she automatically became Princess of Wales. And while technically the title should have passed to Camilla Parker Bowles upon her wedding to Charles, she turned it down out of respect to Diana and is instead known as the Duchess of Cornwall. 

Read more: Everything you need to know about Camilla, Duchess of Cornwall 

However, when Charles ascends the throne, the Duchess of Cambridge is expected to accept this title in honour of Prince William's mother.