The Duchess of Cambridge had a girl Saturday morning in London, giving Prince George a sister and the jubilant British public a new princess.
The baby weighed 8 pounds, 3 ounces, Buckingham Palace announced. The father, 32-year-old Prince William, was present for the birth.
Cheers rang out when the news was announced to a crowd of die-hard royal fans outside St. Mary's Hospital. Many had been camped there for weeks.
An unofficial town crier wearing a regal red coat with gold trim and carrying a homemade scroll rang a bell and announced the birth on the steps of the Lindo Wing, the private ward of the hospital.
"On this day the second of May in the year 2015 we welcome with humble duty the second born of their royal highnesses, the Duke and Duchess of Cambridge," he bellowed. "The princess is fourth in line to the throne.
"God save the queen," he added.
Unlike that of Prince George, this delivery appeared to proceed swiftly. Catherine, the duchess, was admitted to the Lindo Wing in labor at 6 a.m., and the baby was born just 21/2 hours later.
Just 10 hours after that, she and her husband stepped out the door of the hospital to greet the photographers who also had been patiently camped out behind barricades waiting to get the first photo of the newborn.
Catherine was carrying her baby, wrapped in white. The duchess looked at ease and immaculate, dressed in a white and yellow dress.
They waved briefly but did not speak to the crowd before leaving in an escorted car driven by William.
Earlier in the afternoon, William spoke to the crowd briefly when he left the hospital, looking relaxed and happy. He was asked how he and his wife were feeling.
"Very happy, thank you," was his reply.
He drove off at the wheel of a Range Rover, returning later with George, who was brought to the hospital to meet his new sister. The toddler was carried by his father and looked wide-eyed as he waved to the cameras.
This was only the second time the 21-month-old has been seen in public in Britain; the first was the day after he was born at the same hospital on July 22, 2013.
In keeping with tradition, an announcement of the birth was placed on an easel outside Buckingham Palace in the afternoon. It read: Her Royal Highness the Duchess of Cambridge was safely delivered of a daughter at 8:34 a.m. today. Her royal highness and her child are both doing well.
It was signed by the four doctors who delivered the princess.
The news was also disseminated around the world via the palace's official Twitter account.
Prince Charles and his wife, Camilla, Duchess of Cornwall, said they were "absolutely delighted." And a smiling Queen Elizabeth II appeared at official royal duties dressed head to toe in pink.
Congratulatory notes came quickly from Britain's political leaders, who are days away from a general election.
Prime Minister David Cameron posted on Twitter: "Congratulations to the Duke and Duchess of Cambridge on the birth of their baby girl. I'm absolutely delighted for them."
Labor leader Ed Miliband posted: "Congratulations to the Duke and Duchess on the birth of their daughter. Wishing them lots of joy and happiness — and hopefully some sleep!"
The royal family announced in September that William and Catherine were expecting their second child, and speculation was soon rife about its gender. Even the royal couple reportedly did not know.
Bookmakers have been taking bets for many weeks on what the new baby will be called, but it could still be days before a name is announced.
Charlotte is now the odds-on favorite, followed by Alice, with some royalists hoping the child will be named Diana in tribute to William's late mother.
William, Duke of Cambridge, is the queen's grandson, and the new royal baby her fifth great-grandchild. The newborn is fourth in line to the throne, after her grandfather, Prince Charles, her father and her brother.
William's brother, Harry, has been bumped down to fifth place.
After leaving the hospital, William drove his wife and newborn to their official residence, Kensington Palace in London, where they are expected to spend a few days adjusting to life as a family of four before going to Anmer Hall, their 18th century Georgian country manor, on the queen's Sandringham Estate.