Princess Charlotte has just made history with the arrival of her younger brother

Her younger sibling is officially here!

Kensington Palace confirmed this morning that Kate Middleton is in labour, and now they are officially a family of five thanks to the safe arrival of a baby boy.

As with their first two children, all eyes are on the Lindo Wing of St Mary's Hospital in London as we patiently wait to get a glimpse of Prince William and Kate's third child, as well as finding out the little boy's name.

But while most of the attention will be on the new royal baby and his mum this week, Princess Charlotte has just made history with the arrival of her younger brother.

Thanks to the Succession to the Crown Act 2013, regardless of the gender of any younger siblings, Charlotte's place in line to the throne doesn't change. (Prince Harry meanwhile has been bumped down to sixth in line following the arrival of his new nephew. Sorry, Haz.)

So although the new baby is a boy, Charlotte's place in the line of succession is still fourth – and she is the first female royal to not be bumped down the ranks by a younger brother.

That said, there's still this royal rule, which means that Princess Charlotte's children won't automatically inherit her title, solely because she's a girl.

Fortunately there's plenty of time to get that one sorted out – Charlotte is only nearly three, remember.

Not long now until we finally find out the little boy's name!