There’s a logical reason
Well wonder no more, because we’ve got the logical explanation.
Whens she married Wills in 2011, she was given the title of Duchess of Cambridge, however her lesser known name is Princess William of Wales, as women marrying into the royal family take their husband’s name. A bit archaic we know.
Her full title, to be precise, is Her Royal Highness Princess William, Duchess of Cambridge, Countess of Strathearn, Baroness Carrickfergu.
But according to CNN royal expert Victoria Arbiter, the ‘Duchess’ title is more important, hence why she uses. it.
She told Yahoo Style, ‘While Catherine is absolutely a Princess, her correct title is ‘Her Royal Highness the Duchess of Cambridge. She wasn’t born a blood Princess, so she is not a Princess in her own right. When she married William, she took on the rank of her husband, a royal Prince. However, referring to her as ‘Princess Kate’ is simply incorrect.’
As Prince William is also a Duke, and that is his more important title, Kate assumed it herself.
This kind of makes sense, so why was Princess Diana a Princess? Well, again, it was down to her husband Charles.
Charles is a Prince twice over, as he was born one and he was made one (Prince of Wales) in 1969. That second title is the more important of the two, so Diana took the title of Princess.