Britain is greeting the world with an extravagant celebration that includes Bond, the Bard and a Beatle - and a formal welcome from no less a figure than its jubilee queen.

London's seven-year countdown to the 2012 Olympic Games came to a crescendo on Friday night with what promised to be a stunning, imaginative, whimsical and dramatic celebration of the host country.

Fighter jets streaming red, white and blue smoke roared over the Olympic Stadium, packed with a buzzing crowd of 60,000 people, at 8:12 p.m. - or 20:12 in the 24-hour time observed by Britons.

One of Britain's most successful contemporary movie directors, Oscar winner Danny Boyle, was presiding over a three-hour spectacular highlighting the UK's history and impact on the world.

The parade of nations was expected to feature most of the roughly 10,500 athletes - some planned to stay away to save their strength for competition - marching behind the flags of the 204 nations taking part.

Greece had the lead, as the spiritual home of the games, and Team Great Britain was last, as host. The tradition of athletes marching into the stadium by nation at the opening ceremony began at London's first Olympics, in 1908.

It fell to Queen Elizabeth II to formally declare the games open. Last month, the nation put on a festive Diamond Jubilee - a small test run for the games - to mark her 60 years on the throne, a reign that began shortly after London's last Olympics, in 1948.

The Olympic cauldron will be lit with a flame that was kindled May 10, at the birthplace of the anciest Olympics in Greece, from a reflection of the sun's rays off a mirror.

Since then, 8,000 torchbearers, mostly unheralded Britons, have carried the flame on a 70-day, 8,000-mile journey from toe to tip of the British Isles, whipping up enthusiasm for a $14 billion Olympics taking place during a severe recession.

The identity of the last torchbearer, the one to light the cauldron, was kept secret - remarkable given the intense scrutiny at what have been called the first social media Olympics.

Speculation focused on Roger Bannister, the first man to run a four-minute mile, in 1954, and on rower Steve Redgrave, among others.

Boyle's $42 million show, with 15,000 volunteers, promised to take the expected global television audience of 1 billion on a rich and textured journey through British history.

In the center of the stadium, where athletes like Usain Bolt will star in the coming weeks, Boyle constructed a giant set portraying a romanticized vision of a green and pleasant Britain.

Smoke wisped from the crooked chimneys of a homely thatched cottage. Meadows of perky pink flowers, spreads of real grass, fake fluffy clouds and live animals - including 40 cream-colored sheep - transported spectators from the East End of London to a rural idyll so dear to English hearts.

That was later to give way to darker, grittier segments dwelling on the industrial might upon which Britain built a global empire and shaped world history.

Boyle's challenge was daunting: To be as memorable as Beijing's incredible, money-no-object opening ceremony of 2008.

He drew from Shakespeare, British pop culture, literature and music, and other sources of inspiration that will speak to - but perhaps at times baffle - not just Anglophiles but people across the globe.

One segment featured the actor Daniel Craig as James Bond, and former Beatle Paul McCartney was to lead a sing-along.

For Jacques Rogge, it was his last time as president of the International Olympic Committee to watch the Olympic flag being raised at an opening ceremony. He will step down in 2013 after completing the maximum two terms.

Besides the thousands of athletes and performers, 60,000 spectators were expected to pack Olympic Stadium. Political leaders from around the world, US first lady Michelle Obama and her daughters, and a sprinkling of European and celebrity royalty were also attending.