Kate Middleton broke tradition to post a rare personal message on her birthday

The Cambridges are undoubtedly the most talked-about family in the world, with their three children Prince George, Princess Charlotte and Prince Louis entertaining the public on the regular.

Yes, from Princess Charlotte’s signature sass and Prince George’s surprising nickname to Prince Louis’ love of interrupting zoom calls, these miniature royals never fail to make viral news.

It is the Duchess of Cambridge and her 'aura of perfection' that makes the most headlines however, from her multiple public appearances to her candid words about motherhood.

This weekend, it was her birthday that got the world talking, with the Duchess of Cambridge turning 40 over the weekend.

The royal family came out in force to shower the Duchess with well wishes and it is thought that William and the Cambridge children treated her to a day of 'low-key celebrations'.

The main talking point however was the trio of official portraits released by the palace to mark her 40th birthday, set to be displayed in the National Portrait Gallery's permanent collection.

The photographs, taken by Paolo Roversi, instantly went viral, raking in millions of likes.

In fact, the public outpouring of love was so great that the Duchess broke tradition and shared a personal message in response.

'Thank you for all of your very kind birthday wishes, and to Paolo and the National Portrait Gallery for these three special portraits,' Kate captioned the final photograph, signing off as 'C'.

Well that sounds lovely.

Happy birthday to the Duchess!