Princess Charlotte may be just two years old, but ahead of the arrival of her new baby sibling, she could be on track to make royal history.
Catherine and William’s daughter is currently fourth-in-line to the throne, behind her grandfather Charles, dad William, and brother George.
But now the Duke and Duchess have welcomed a little boy, Charlotte will be the first ever female member of the royal family to retain her position in the line of succession to the throne.
In previous years, Princess Charlotte would have been bumped down to fifth-in-line, were the Duchess of Cambridge to give birth to a boy.
But due to a change in the Succession to the Crown act in 2013, which sees the line of succession based solely on birth order rather than gender, that will no longer be the case. Charlotte will remain fourth-in-line to the throne ahead of any younger brothers.
The change to the rule was brought into force when Catherine was pregnant with Prince George.
The 300-year-rule was changed to ensure that a possible first-born daughter of Prince William and Catherine could take precendence over any following younger boy siblings.
It’s expected that following the birth of her new son, the Duchess of Cambridge will lay low in public, until the wedding of brother-in-law Prince Harry and Meghan Markle.
Catherine is currently on maternity leave from royal duties, and is not likely to return to her official responsibilities until some months after welcoming her new baby.