However, as Kate would be married to a King rather than reigning in her own right, she won't become Queen in the same way that Her Majesty Queen Elizabeth II is. Once Prince William takes the throne and becomes the King of England, Kate will then become Queen Consort.

When Prince William becomes king Will Kate become queen?

As the royals climb the ranks, their titles are also subject to changes. For example when Prince William becomes King, Kate Middleton will be known as Queen Consort, a role that she is reportedly already preparing for, and Prince George could inherit his father's Dukedom.

Will Kate be called Queen Catherine?

As for when Prince William eventually takes over from Prince Charles as the reigning monarch, Kate will then undergo a further title change and likely be known as Queen Catherine. Officially, she will be Queen consort, as she doesn't have any royal blood herself but rather married into the family.