It was a day which ended as unexpectedly as it had begun.
Having given the world's media the slip when they arrived at St Mary's Hospital shortly after 5.30am, the Duke and Duchess of Cambridge kept the birth of their baby boy a secret for more than four hours before making an announcement by email just before 8.30pm last night. Instead of the "theatre" of an official bulletin being driven from the hospital's private Lindo Wing to Buckingham Palace, to be placed on an easel for the waiting world to see, Kensington Palace changed the plan at the last minute.
Moments before a Jaguar pulled up outside the hospital to take the all-important piece of paper across London, the Palace emailed journalists and newsdesks to announce that the Duchess had given birth to an 8lb 6oz son. It was one more piece of stage management after a week in which the Duke and Duchess had managed to remain in complete control of the way their historic news was reported.
The world's media had been camped outside St Mary's for weeks in the hope of being first with the news of her hospital admission, but when the Duke and Duchess finally arrived at St Mary's Hospital early yesterday morning, the only person who caught sight of them was Jesal Parshotam, a freelance photographer. And by the time he realized which entrance they were heading for, they were already inside.
He had the consolation of being the first to publish the news, which came, with a certain inevitability, via Twitter, when he sent a tweet at 5.55am saying: "Kate Middleton has gone into hospital."
His tweet was treated with skepticism by newspapers and broadcasters who had already seen one too many false dawns. They began calling Kensington Palace, who stonewalled for more than half an hour until the Duchess had been seen by her medical team and was "settled" in her private room at the Lindo Wing.
Only then, at 7.28am, did the Palace issue official confirmation that the Duchess was in labour and had been admitted. In truth, aside from one little-noticed tweet, the final weeks and days of the Duchess's pregnancy had been a master class in stage management, during which the media did not once manage to photograph her or second-guess her plans.
The Duchess, 31, chose to spend almost all of last week with her parents at their Georgian manor house in Bucklebury, Berks, where she was joined last Monday by her husband.
The house, which the Middletons bought for pounds 4.7?million last year, is down a quiet country lane, with tall hedges protecting its gardens from prying eyes, and has 18 acres of land.
In the middle of the afternoon on Friday, which was, according to one source, the Duchess's due date, she and the Duke slipped out of Bucklebury, unnoticed by locals or the handful of freelance photographers keeping an eye on the surrounding lanes, and returned to their London home at Kensington Palace. The Palace, where extensive renovations are still being carried out to the large apartment which will become the couple's new family home, is less than five minutes' drive from St Mary's.
It meant the Duchess could now be certain that her baby would be born in the Lindo Wing, rather than at the Royal Berkshire Hospital in Reading, which was "plan B".
The first sign that a birth might be imminent came at 10pm on Sunday night, when royalty protection officers drove around the entrances of St Mary's in a "dummy run" witnessed by photographers and TV crews.
But shortly after 5.30am came the real thing. Once again, the Duke and Duchess's staff had thought out every detail, and chose a dark blue Ford Galaxy people carrier to drive the Duchess to the hospital, rather than the Range Rovers, Land Rover Discoveries and Jaguars they normally use.
An aging Saab 95 was used as the police back-up car to further confuse anyone watching out for a motorcade of "royal" cars, and the couple were taken to a rear entrance of the Mary Stanford wing at St Mary's, which joins onto the Lindo Wing. They were spotted by Mr Parshotam, but he was not quick enough to get to the entrance before the Duke and Duchess were inside the hospital, meaning none of the photographers who had been staking out the building since the start of July managed to get a picture of the Duchess arriving.
Diana, Princess of Wales, used the same entrance when she was admitted to the Lindo Wing to give birth to Prince William in 1982.
With no pictures of the Duchess to sell, Mr Parshotam used Twitter to make a virtue of his sighting of the couple.
His 5.55am tweet was followed seconds later by his colleague Darren Sacks, with whom he had shared the news, who tweeted the rather less restrained: "World Exclusive Duchess of Cambridge is in labour!!!"
Luckily for Kensington Palace, the tweets were treated with a pinch of salt by the mainstream media, which had endured false alarms on an almost daily basis for weeks on end.
Mr Parshotam, 24, said he and his friend Mr Sacks, 30, had been at the hospital since 8pm the previous night.
He said: "We were just standing outside chilling and talking and then it all happened. The cars showed up. They were very, very simple cars - it was very discreet . . . the protection officers jumped out and they all rushed in. It was a very swift manoeuvre. The Duchess went in and the cars were gone very quickly - within a minute. That was it." When the Duchess's staff began receiving phone calls asking if the tweets were correct, they merely batted away questions by saying, as they had done on previous occasions, that they "wouldn't comment on speculation".
One Palace insider said: "It was important to us that the couple were inside the hospital, that the Duchess was settled and that she had been seen by medical staff before we confirmed anything."
The waiting photographers had also missed another sign that the Duchess was about to give birth: Marcus Setchell, the Queen's former gynaecologist and the man chosen to supervise the birth, had arrived at the hospital shortly after the Duchess, having been woken at his home in north London to be told he was needed. Following the 7.28am update, there was nothing more from the Palace for the next 13 hours.
Unknown to the journalists and hundreds of well-wishers waiting in the 31C heat outside, the Duchess had given birth at 4.24pm. But the first indication that the news might be imminent was when Kensington Palace announced at 7.58pm the change to the way the baby's arrival would be announced.
That put the media on alert, and half an hour later it was official: Britain had a new king-in-waiting.