All eyes will turn to London on Friday for the opening ceremony of the 2012 Olympics, which begins at 2000 GMT and ends more than three hours later.
The three-hour showcase created by Oscar-winning "Slumdog Millionaire" director Danny Boyle will be watched by a crowd of 60,000 in the main stadium built in a run-down area of London's East End and a global audience of more than a billion.
Spectators will be urged to join in sing-a-longs and help create spectacular visual scenes at an event that sets the tone for the sporting extravaganza, when 16,000 athletes from 204 countries share the thrill of victory and despair of defeat with 11 million visitors.
The Games will also answer the question on Britons' lips were seven years of planning, construction and disruptions, and a price tag of $14 billion during one of the country's worst recessions, actually worth it?
A tense moment
"This is a very, very tense moment but so far I'm cautiously optimistic," said Boris Johnson, mayor of London, the only city to host the Summer Games three times.
"I'm just worried that I haven't got enough to worry about at the moment," added the mayor, known for his witty asides.
Counter-terrorism chiefs have played down fears of a major attack on the Games, and British Prime Minister David Cameron said that a safe and secure Olympics was his priority.
"This is the biggest security operation in our peacetime history, bar none, and we are leaving nothing to chance."
A series of doping scandals have tarnished the Games' image in the buildup, with at least 11 athletes banned so far, and Greek triple jumper Paraskevi Papachristou became the Olympics' first "twitter victim" when she was withdrawn from the team over tweeted comments deemed racist.
Queen Elizabeth will be in the crowd, along with US First Lady Michelle Obama and a host of dignitaries and celebrities.