At the end of the three-hour ceremony, the Queen will declare open the Games of London and the Olympic cauldron will be lit.

The ceremony comes at the end of a day that has seen the Olympic torch complete its 70-day odyssey around the British Isles.

British Prime Minister David Cameron said the country would show the world "the best of Britain" over the next two weeks after describing previews of tonight's opening ceremony as "spine-tingling".

Cameron pledged Britain was ready to welcome the "greatest show on earth" after US presidential hopeful Mitt Romney cast doubt upon the country's readiness yesterday.

Jacques Rogge, president of the International Olympic Committee (IOC) added: "London is ready."

US First Lady Michelle Obama, who is leading the US presidential delegation which includes a ringside seat at tonight's ceremony, was also in east London to give her own personal good luck message to Team USA.

Mrs Obama urged America's athletes to "have fun, breathe a bit, but also win", as she met them at their training base.

Oscar-winning director Boyle said the curtain-raiser at the Olympic Stadium was fitting both for London and everyone who will compete at the Games.

Millions more globally are expected to tune in on television but many competitors will be missing from the long and late-starting athletes' parade.

Competition clashes or just preferring to rest instead as part of vital preparations mean that many will skip the ceremony.