THE British Queen has issued a formal decree to grant the title of prince or princess to all of the Duke and Duchess of Cambridge's children.
Using Letters Patent, a method by which the sovereign can give orders without the involvement of Parliament, the Queen decided that from now on "all the children of the eldest son of the Prince of Wales" should be given the title of Royal Highness "with the titular dignity of Prince or Princess prefixed to their Christian names".
Until now, only the eldest son of the eldest son of the Prince of Wales was entitled to the honour, following a decree made by George V in 1917, meaning that if the Duke and Duchess of Cambridge have a daughter later this year she would have been known as "Lady".
But the Queen's formal ruling, officially made on December 31 but only now made public, means that not only the eldest child but all children of the Duke and Duchess will be princes and princesses.
A formal announcement in the London Gazette reads: "The Queen has been pleased by Letters Patent under the Great Seal of the Realm dated 31 December 2012 to declare that 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."
The Government has already begun the process of altering the laws of succession to ensure that the Duke and Duchess's first child will become monarch, removing the ancient rule of male primogeniture which gave precedence to boys.
However, the Queen's decree, in specifying that the royal titles are only given to the children of the Prince of Wales's eldest son, means that if the Duke and Duchess have a daughter, she will not be entitled to give her own children the title of prince or princess.
The Duchess celebrated her 31st birthday today by spending time privately with her husband, who had time off from his job as an RAF Search and Rescue pilot.
The Duke is understood to have travelled to the South East from his base in Wales to spend time with his wife in London.
Gordon Rayner, Telegraph.co.uk