Many people like to think they know the royals pretty well.
From watching their marriages, divorces, births, deaths and seeing all their drama unfold through the tabloids, when something happens in the royal family it is not often that people are left too surprised.
But it turns out their is one fact that quite a few people didn't realise about the royal family. And that fact is that Prince Harry and Prince William have another brother. And a sister, too.
To be fair, they are step-siblings. But siblings all the same.
Tom Parker-Bowles and Laura Lopes are Camilla, Duchess of Cornwall's children from her previous marriage with Andrew Parker-Bowles.
When Camilla and Charles married in 2005, Charles being their stepfather.
Tom is 45 years old, while Lisa is 42.
The revelation came for many after a new promo for Tom Parker-Bowles cooking show appeared in their social media newsfeeds.