Fireworks at the opening ceremony of London 2012
The Queen has declared the London Olympics officially open, before seven young athletes were given the honour of lighting the ceremonial flame, reports the BBC.
Flag-bearer Sir Chris Hoy earlier led out Team GB, who were dressed in white and gold tracksuits, to loud applause.
Games chief, Seb Coe welcomed the world to London, saying the event celebrates "what is best about mankind".
The three-hour spectacle, a quirky take on British life, was watched by TV audiences around the world.
The show featured celebrities and sportspeople from all walks of British life, including David Beckham, Bradley Wiggins and actor Daniel Craig as James Bond.
The identity of who was to light the symbolic flame had been shrouded in secrecy ahead of the ceremony.
Opting for young athletes over one of Britain's sporting greats, the group of seven each lit a single tiny flame on the ground, which triggered the ignition of more than 200 petals.
Long stems on the cauldron then rose towards each other to signify unity.
The show started with iconic images of London and Britain being beamed to the world, and all four countries of the UK were represented in song.
The field at the stadium in Stratford in east London was turned into a green meadow, with a cast of 10,000 volunteers taking roles from British history.
The show took the watching world through "great revolutions in British society", from an agricultural setting through to the Industrial Revolution itself.
Steelworkers began forging material that transformed into golden Olympic rings, which lifted into the air to be suspended above the performers.
There were cheers too as the crowd saw a film featuring an unlikely meeting between the Queen and the 007 James Bond.
"Good evening Mr Bond," the Queen said in the clip, before they left together, apparently heading towards the Olympic Stadium in a helicopter.
A helicopter then flew over the stadium to the sound of the Bond theme tune, as two figures parachuted down, one dressed as the monarch.
As if by magic, the Queen appeared in the stands - part of a crowd of about 80,000 - amid cheers.
The BBC's Claire Heald, at the stadium, says: "It was quite quiet among the crowd, after the excitement of a sky-diving Queen. But Bowie, Queen (as in the band!) and New Order fit the sparkle of the stadium and lift the mood."
The ceremony also celebrated the National Health Service by featuring a cast of 1,200 volunteers recruited from hospitals all over the country, including Great Ormond Street children's hospital in London.
Another tightly-kept secret was how the torch would make its final journey from central London down the River Thames to the stadium in east London.
That job fell to former England football captain David Beckham, who was shown steering a speedboat past Tower Bridge.
A spokesman for Games organiser Locog confirmed that the star drove the boat down the river live. "A bit of the close-up was pre-shot but he drove it live," he said.
The athletes taking part in the Games - led, as tradition dictates, by the Olympics' spiritual home Greece - made laps of the stadium bearing their nations' flags. There were huge cheers for the Irish team - and for Usain Bolt, carrying the flag for Jamaica.
Team Nigeria was decked in traditional attire when they entered the arena as part of the march past. They were behind Niger in the alphabet pecking order of the march past.
And Wiggins, wearing a yellow jersey, rang the largest harmonically tuned bell in the world to launch the opening ceremony.
As the show began, its artistic director Danny Boyle pledged a ceremony with a theme of "this is for everyone".
The Oscar-winning film director added that it contains "a celebration of the creativity, exuberance and, above all, the generosity of the British people". He said there were to be "no spectators - everyone in the stadium will be part of the magic".