The landmarks across London were lit in hues of red, white and blue to celebrate the birth of first child of Prince William and Kate Middleton. The baby was born with William at Kate's side at 4:24 p.m. (1524 GMT) and weighed 8lbs 6oz (3.8 kg).
"The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall, Prince Harry and members of both families have been informed and are delighted with the news," Clarence House, Prince William's office, said in a statement.
"Her Royal Highness and her child are both doing well and will remain in hospital overnight."
The royal birth has provoked a media frenzy, with national and international media keeping up a deluge of speculative reports throughout Monday from outside the hospital.
Crowds gathered outside the hospital and Buckingham Palace, eager to hear news of the birth. The BT Tower in central London announced the birth with an illuminated scrolling sign.
Presented by Adam Justice