Streaming red, white and blue over Buckingham Palace, it drew to a close one of the biggest celebrations in Britain's royal history in majestic, albeit rainy, fashion.
The booming 60-gun salute, the carriage procession, the distant, yet intimate balcony appearance, and the rousing rendition of the National Anthem.
Many who witnessed it in person felt London - maybe even the world - had never seen anything quite like it.
"We're the envy of everyone with these events," said Margaret Barker, 70, from Middlesbrough. "Nowhere else puts on a show like us."
Some had camped out after Monday's concert to make sure they were in the front row for the closing moments.
Others had made their home in this place - sodden sleeping bags and all - for the whole of the long weekend.
But the crowds on The Mall - 30 deep in some areas - were quick to remind anyone who asked that their sacrifices - a comfy bed, a hot dinner, a comforting cuppa - were all worth it for the Queen.
As Lisa Maysey, 40, a paramedic, from Ashford in Kent, pointed out: "She puts the Great in Great Britain."
However, it was that clear the Duke of Edinburgh, absent because of ill health, was also very much in people's thoughts.
"Three cheers for Prince Philip!" shouted a loud voice from the back - and The Mall was happy to oblige.
There were comical moments too.
A wayward horn prompted laughter from the crowd amid the pomp of a military drill - although not a single smirk could be seen on the faces of the bayonet-carrying, bearskin-clad guards.
The celebrations had begun many hours earlier for the thousands who gathered at St Paul's Cathedral.
With bells pealing loudly, and yellow-liveried trumpeters standing to attention on the stone steps, the royal entourage arrived for a service of thanksgiving - with a sermon delivered by the Archbishop of Canterbury, Dr Rowan Williams, and broadcast on loudspeakers for all to hear.
Fathers lifted small children onto their shoulders and well-wishers clambered on pillars around the cathedral, waving their flags and breaking into spontaneous song as the monarch pulled up in her state Bentley.
Once again, Prince Philip was not forgotten. Patricia Middleton, 60, from west London, observed: "Today has been wonderful - people are in such a great mood.
"The only thing that's sad is that Philip can't be here, but of course the Queen is carrying on - because she's fantastic."
As the day progressed, the focus switched to Parliament Square to see the Queen arrive at Westminster Hall for a lunch with 700 guests.
They dined on a pan-UK feast of marinated Uist Island salmon, Lyme Bay crab, Welsh Cambrian lamb, Isle of Wight asparagus, and Jersey Royal potatoes.
Away from the capital, Southampton celebrated as the cruise company Cunard sailed its three ships - Queen Victoria, Queen Mary 2 and Queen Elizabeth - into port together in single file for the first time.
A display by the Red Arrows over the seaport city on Tuesday evening was unfortunately cancelled, but there will be a fireworks display before the ships leave port from 23:00 BST.
Street parties also continued around the UK. At one, in Mold, in Flintshire, they jived and jitterbugged all day long at a 1950s-themed do.
This fourth day of celebrations, taking place on an extra bank holiday, came after many other memorable events to mark the monarch's reign.
On Saturday, Her Majesty attended the Epsom Derby, indulging her passion for horse racing, and on Sunday, according to the organisers of the Big Jubilee Lunch, some six million people stubbornly ignored the unkind weather to take tea and sandwiches with friends and neighbours.
Among them were Prince Charles and the Duchess of Cornwall who attended a lunch in London's Piccadilly, stopping to chat to those eating their food in the drizzle.
Later that day, an historic 1,000-strong flotilla glided down the Thames and according to organisers, more than a million people turned out to watch.
Then on Monday thousands attended a special Diamond Jubilee picnic in the grounds of Buckingham Palace and enjoyed a picnic hamper created by chef Heston Blumenthal - perhaps, thankfully, without his signature snail porridge or bacon and egg ice cream.
The ticket holders then joined the Queen and the Royal Family to watch a concert in front of the palace.
Featuring performances by Robbie Williams, Kylie Minogue and Sir Elton John among others, it drew many thousands more onto The Mall to watch on big screens.
It all ended with a firework display and more than 4,000 beacons being lit in the UK and around the world - the final one by the Queen herself.
Not everyone joined in the festivities, with members of the anti-monarchist group Republic staging demonstrations over the whole four days.
But in most places, there were smiles - most notably from the Queen herself, who beamed her appreciation to the masses below the Buckingham Palace balcony.
With several celebratory cascades of rifle fire and three absolutely enormous cheers for Her Majesty, it was a spectacular way to end to the Diamond Jubilee.
In a glittering Union Jack top hat, Anne Hall, 67, from Filey in North Yorkshire, summed up the sentiment of those on The Mall.
"It makes you proud to be British."
In the final moments of Tuesday's festivities, the rapturous applause of thousands who had gathered on The Mall to see the Queen was drowned out by a deafening RAF flypast.