The Duchess of Cambridge safely delivered a daughter at 8.34am today, Kensington Palace has confirmed.
The royal birth took place shortly after Kate arrived at hospital.
Kate was admitted to the private Lindo wing of St Mary's Hospital in Paddington, London, at 6am this morning, where she was accompanied by her husband Prince William.
Kensington Palace tweeted: “The baby weighs 8lbs 3oz. The Duke of Cambridge was present for the birth.
“The Queen, The Duke of Edinburgh, The Prince of Wales & The Duchess of Cornwall, Prince Harry & members of both families have been informed.
“Her Royal Highness and her child are both doing well.”
Duchess Of Cambridge Labour - Live Images
It is the second child for the Duke and Duchess of Cambridge and a younger sibling for Prince George.
Just a day later the little boy made his debut to the world media as he was pictured on the steps of the hospital in his mother’s arms.
The hospital has been a royal favourite for generations
The hospital is also where Prince William was born and indeed the newborn Duke was photographed in Princess Diana’s arms in the same spot 32-years-ago. Prince Harry was also born there, as were Peter and Zara Philips.
Delivery packages including a one-night stay at the Lindo wing of St Mary’s Hospital range from £5,215 - £6,745. Extra nights cost from £945 to £1,155.
The expectant mother and her visitors can access the internet via wifi and there is a choice of daily newspaper delivered to the room each morning. Toiletries are also provided.
All meals are freshly prepared in a dedicated kitchen and tea and coffee is provided for mothers and guests throughout the day.
The wing also offers a "comprehensive wine list should you wish to enjoy a glass of champagne and toast your baby's arrival".
William and Kate 2013/Diana and Charles 1982
