As you probably already know, there's a new royal baby in the world!
What you might not know is that the birth of this royal boy, the fifth in line to the throne, marks a huge, historic first for the British royal family.
For the first time in 900-plus years, a newborn prince will not automatically skip ahead of his older sister in the line of succession.
The Succession to the Crown Act 2013 ended male-preference primogeniture in the British succession, meaning that a royal child's gender no longer matters when it comes to what number they are in line to the throne — it's all about birth order.
To keep things from getting too confusing, the act isn't retroactive and only applies to royals born after Oct. 28, 2011. So, for example, Princess Anne, the Queen's second child, is still behind her younger brothers, Prince Andrew and Prince Edward, in the line of succession.