People around the globe have been toasting the birth of the second child for the Duke and Duchess of Cambridge.
Celebrations have stretched from the Lindo Wing at St Mary's Hospital in Paddington, across the UK, to the other side of the world.
And, of course, British political leaders could not avoid weighing in with congratulations five days ahead of the general election.
Katrien Grobler, the historical visitor
I'm from South Africa, I've been in London for four months.
I thought I'd go along and arrived about five minutes before the announcement.
I'm shaking with excitement, the atmosphere is amazing! There are at least 1,000 people here. Most of them are photographers!
There are people with flags; people just want to be part of it. It's part of history and I just want to be here!
Meanwhile @zach_dovey, working at the hospital, was caught out by the announcement, tweeting: "Turning up to do an A and E shift at St. Mary's Hospital and had forgotten about #theRoyalBaby shenanigans".
Julie Lischer, the anglophile abroad
I live in Marietta, Georgia, in the USA. Congratulations on the new baby girl!
We held a shower for the royal baby. I served scones and cucumber sandwiches and all kinds of Royal treats. I invited my friends. Everyone came in their finery and hats.
We took up a collection of five US dollars per person and I send that money to one of Kate and Will's favourite charities.
We also had a shower for baby George and did the same. I received a lovely thank you card from the Duke and Duchess of Cambridge. When I opened my mailbox and saw the Buckingham Palace postmark I almost fell over.
We were on assignment in Cobham, Surrey, with my husband's job in 2007-2010. I fell in love with your country.
I flew back for the Royal wedding in 2011. I was one of the thousands of people out on the mall cheering and snapping photos!
Rebecca Henley and Jeremy Maynard, the accidental tourists
We went to the see the canal boats at Little Venice, but we stumbled on the Lindo Wing and all the hype. There were hordes of people.
We saw Wills, he was waving to the crowd. We chatted to a police lady. She said she was there when George was born.
It was exciting, thrilling. The crowd was hilarious. It was funny to see so many people out in support.
The people from the press were arguing among themselves and trying to attach cameras to the hospital walls.
There's also been a huge reaction on social media generally, with journalists, politicians, businesses and the public sharing #royalbaby facts, tributes and well wishes.
The BT Tower in central London displayed a message announcing it was a girl, and Tower Bridge is set to be lit pink later this evening in celebration of the birth of the princess.
The party leaders were out in force on social media too, offering the good wishes to the royal couple... the reception the politicians got on Twitter, however, was less warm.
The bonhomie even seemed to have spread north of the border with SNP leader Nicola Sturgeon adding her congratulations to the list, and being received with equal disdain from her constituents...
Some were tweeting more than others, but even that didn't stop people weighing in and offering their thoughts on perhaps more political issues in response.
And finally UKIP Leader Nigel Farage urged UKIP candidates to take an hour out to toast the arrival of the new royal.
Written by Kerry Alexandra and Richard Irvine-Brown