Kensington Palace have announced that the Duchess of Cambridge delivered a baby girl at 0834hrs this morning.
The baby, which weighed 8lb 3 oz, will be fourth in line to the throne.
The Queen, the Prince of Wales and other members of the Royal Family have been informed and the Duchess and the baby are said to both be doing well.
The news will particularly please the Prince of Wales who said during an engagement this week he had hoped for a granddaughter. Prince William was also rumoured to have been hoping for a girl.
All eyes will now be on the doors of the Lindo Wing for the first glimpse of the latest addition to the Royal Family and speculation will now turn to the name of the Princess.
The two top choices with bookmakers are Alice and Charlotte, with Victoria and Elizabeth also high on the list of likely names.
The newborn will not only have British eyes on her but the interest of the Commonwealth countries she will also be a Princess in the 53 member states.