Royal baby's place in history
The birth of the Duke and Duchess of Cambridge's baby will mark the first time since 1894 that House of Windsor has three generations in line to throne at same time.
The Queen ensures HRH title for royal baby
Under past rules, only a first-born boy of the Duke and Duchess of Cambridge would automatically have become a Prince. A daughter would have been styled Lady instead of Princess and not known as Her Royal Highness.
The Queen issued a Letters Patent under the Great Seal of the Realm when Kate was around three months pregnant declaring:
"All the children of the eldest son of the Prince of Wales should have and enjoy the style, title and attribute of royal highness with the titular dignity of Prince or Princess prefixed to their Christian names or with such other titles of honour".
When William was born he was Prince William of Wales and his children will use Cambridge in the same way, becoming HRH Prince (forename) of Cambridge or HRH Princess (forename) of Cambridge.
According to the monarchy's official website: "For the most part, members of the Royal Family who are entitled to the style and dignity of HRH Prince or Princess do not need a surname, but if at any time any of them do need a surname (such as upon marriage), that surname is Mountbatten-Windsor."
-
In pictures: Royal couple naturals around children
Kate and William have spoken of their desire to start a family of their own and have shown themselves to be naturals around children.
-
Growing up as a future heir to the throne
What will life be like for the Duke and Duchess of Cambridge's baby, growing up as the future heir to the throne?