LONDON, England (AP) — With the flame comes the games.

After years of preparation and months of buildup, London’s Olympic moment finally arrived last night.

Royal Marine Martyn Williams carried the Olympic torch as he rappelled down from a Royal Navy Sea King helicopter into the Tower of London on the shore of the River Thames. The commando’s grand entrance plunged the symbol of the games into the city’s historic heart, bringing Olympic pageantry to the British capital that last held the event in 1948.

Crowds lined the city’s famed river banks to see the torch arrive, while Yeoman warders — the ceremonial Tower guards popularly known as Beefeaters — looked on from inside the landmark’s grounds.

For Londoners, the arrival of the torch ignites a time of excitement — as well as four weeks of extreme crowds and transport strains.

Organisers have tried to smooth the way. London Underground subway lines are festooned with large magenta and pink signs pointing routes to the Olympic venues. Cartoony ads with wide-eyed horses and beefy musclemen warn commuters to remember that Olympic competitions are taking place and to rethink their daily journeys. Barriers are being erected to mark the special traffic lanes for Olympic vehicles — disparagingly dubbed “Zil lanes”, after the limousines granted exclusive use of special lanes on Soviet-era highways.

Londoners who already struggle to get to work on any given weekday aren’t convinced all will be well — and haven’t been shy about saying so. The atmosphere of gloom has been segmented by the never-ending rain and a constant stream of headlines about the failure of security contractor G4S to provide enough guards.

The mayor has a message for the naysayers: “Put a sock in it.”

Speaking at a ceremony at the Tower of London, Johnson said the arrival of the torch would dispel any last remaining clouds of dampness and anxiety.

“It will spread the crackling bushfire of Olympic enthusiasm throughout this city and the country,” he said, as Kelly Holmes, a British double gold medal winner in 2004, toured the ramparts of the landmark, with the torch held aloft.

Ready or not, the games are a reality. Olympic banners in hot pink, acid yellow and lime green have painted London in neon. The tubby Cyclops-like mascots, Wenlock and Mandeville, are dancing around central London tourist attractions in a desperate bid to be huggable. The city’s famous red double-decker buses are sporting ads flogging the last of the unsold Olympic soccer tickets.

The stadiums themselves are nearly ready. At the athletes village, Cuba and Denmark have been the first to drape flags off their balconies. The Olympic clock ticking down the days in Trafalgar Square has reached single digits.

Olympic historian David Goldblatt, co-author of “How to Watch the Olympics,” said the flame’s arrival in London marks a key turning point.

“I think it signifies the moment when everyone, whether for, against or indifferent, is thinking ‘Oh Lord let’s just get the bloody thing started’,” he said.

It was only weeks ago that celebrations marking Queen Elizabeth II’s Diamond Jubilee sent Britons into a spasm of patriotic flag waving and “God save the Queen” singing as they watched a flotilla of 1,000 boats on the River Thames. Will the flame’s arrival inspire the famously inhibited British to do it all again — to cheer and wave and weep and be inspired — as the torch relay winds through the city’s 33 boroughs?

Could be — if the first 62 days of the torch’s travels are any indication.

The 8,000-mile (12,900 kilometre) torch relay has already been a cultural happening across the length of Britain, drawing crowds out to meet it wherever it goes. Spectators in rain ponchos have flash-mobbed to its side, hoping for that once-in-a-lifetime chance to touch a bit of history. Some have even stood by the side of the road to see the trucks that carry the torch between cities, as it fulfills a promise to travel within 10 miles (16 kilometres) of 95 per cent of Britain’s population.

“Both the Diamond Jubilee and the Olympics are like carnivals or tribal festivals,” Kate Fox, the author of “Watching the English”, wrote in a British Airways survey on the games. “We behave in ways we wouldn’t normally behave — dancing in the streets and waving flags and shouting and cheering and indulging in other wildly disinhibited acts, such as maybe even talking to strangers.”

Britons were even more committed to the flame before the last London Olympics in 1948, when the torch was actually run in a relay from the site of ancient Olympia in Greece. Janie Hampton, author of “London Olympics: 1908 and 1948”, said runners traveled continuously day and night. Crowds emerged to see the 1948 flame even in the middle of the night.