Prince William and Kate Middleton's third child--a boy!--arrived on Monday, hours after the Duchess was admitted to a London-area hospital in early labor. "Her Royal Highness The Duchess of Cambridge was safely delivered of a son at 1101 hrs. The baby weighs 8 pounds, 7 ounces," Buckingham Palace said in a statement. "The Duke of Cambridge was present for the birth. Her Royal Highness and her child are both doing well. 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." The baby boy joins 4-year-old brother Prince George and 2-year-old sister Princess Charlotte. Kate and William's third child, whose name has yet to be revealed, with be fifth in line for the throne, bumping Prince Harry down to sixth in line.