This is the tenth in a series of dispatches from around the country.

Tuesday 4 June

Day four of the Jubilee weekend and Green Park, across the road from Buckingham Palace, is deep in huge piles of litter.

It is not a good omen. Last night developed into one enormous party. Can it really continue today? Well as it happens it can, and does.

The Gold State Coach was built for George III in 1760

The Queen leaves for a thanksgiving service at St Paul's in the Gold State Coach, a baroque extravaganza straight out of an impossible lavish production of Cinderella which hasn't been used in anger since the Silver Jubilee of 1977.

But, though it may look spectacular, it is notoriously uncomfortable: one previous monarch used to get seasick while riding in it.

While we wait for her return we are entertained by the amplified music of bands, pipes, orchestras.

The numbers around the palace, in the Mall and the royal parks, swell steadily. There are regular estimates from the police: 600,000... 800,000... a million.

Carnival atmosphere

At lunchtime a massive sequence of processions down the Mall begins.

Devised by Sir Michael Parker, it was paid for out of the �6m raised from business sponsors in seven short months by Lord Sterling, chairman of the Golden Jubilee Weekend Trust.

As he is fond of pointing out, though doubters wondered if Britain was ready to celebrate the jubilee, business leaders seemed to have few qualms and were happy to stump up.

Carnival fun courtesy of Notting Hill performers

The procession is a mixed bag - deliberately so. It is designed to remind us how Britain has changed in 50 years, and to celebrate the diversity of modern British society.

Fifteen hundred performers from the Notting Hill Carnival come in spectacular costumes - colourful, yes, but looking less impressive in the wide open spaces of the Mall than in the narrow streets of Notting Hill itself.

Patti Boulaye's 5,000-strong gospel choir are a highlight, making a glorious noise. So too is the procession devoted to 50 years of Britain's services: from the AA to the armed forces, via the police, fire brigade, ambulance service, scouts and guides, boys' and girls' brigades and Chelsea Pensioners.

Hell's angels

The pensioners get one of the biggest cheers of the afternoon, as they march smartly past to the sound of a military band.

There's another great cheer for the band of Hell's Angels who roar up the Mall and screech to a halt in front of the Queen, who has by now returned from lunch at the Guildhall and processed down the length of the Mall herself in an open-top car, escorted by hundreds of children bearing golden streamers.

A million people turned out for the celebrations

She sits now on a special platform alongside other members of her family at the foot of Queen Victoria's statue, just in front of Buckingham palace.

Thing start to overrun terribly. A great sequence of carnival floats celebrating 50 years of British society and another devoted to the Commonwealth glide by; no-one seems to know quite what it's all meant to represent.

Air display

But the collective good humour is too great. If people are bored they aren't showing it. And the good humour is said to extend even to the streets far away from the Mall, where many thousands are milling about with no way of knowing what's happening down at the palace.

And so too the climax of the afternoon. The Queen walks into the palace and out onto the balcony. A million people roar and wave their flags and roar some more. The amplified orchestra strikes up Land of Hope and Glory.

A flypast signals the end of the party

And then - a full half hour late - a flypast of 27 British aircraft (including a solitary Eurofighter, soon to be rechristened the Typhoon) culminating in an extraordinary sight: Concorde escorted by nine Red Arrows, sailing smoothly along the length of the Mall in a deafening roar and trailing clouds of red, white and blue smoke.

Twice more the Queen appears, twice more they sing and wave their flags in an orgy of benign nationalism. And then it's over. The noise subsides, the crowds start to disperse.

Royal support

Afterwards Lord Sterling says the Queen was in sparkling form. Who after all could fail to be moved and gratified, even overwhelmed, by such adulation?

What does it all mean? The Guardian columnist Polly Toynbee, a republican, reckons it signifies nothing more than people's willingness to enjoy a good party if one is laid on for them.

But the thousands outside the palace with their flags weren't just there for a party: they were there to celebrate a person and an institution.

Onlookers get into the spirit

You can, as Lord Sterling says, arrange the most splendid party but if people don't want to come they won't.

The multitude in London, and the thousands more who went to street parties and garden parties around the country, knew precisely why they were partying.

Despite all the vicissitudes of recent years, despite the huge changes of the last 50 years, despite the disappearance of many of the old values and of the automatic deference which animated much of British society at the start of the Queen's reign, the monarchy - and especially the Queen herself - clearly still have an important place in the hearts of many of her subjects