In his final news conference before the Games, International Olympic Committee President Jacques Rogge paid tribute to the host nation.
"Great Britain was the cradle of modern sport," Rogge said. "You invented modern sport in the second half of the 19th century."
To underline the point, Bradley Wiggins, newly crowned as Britain's first winner of the Tour de France and hoping to add more road cycling gold in London, tolled the world's largest tuned bell to signal the start of the ceremony.
More than 10,000 athletes from 204 countries will compete in 26 sports over 17 days of competition in the only city to have staged the modern Games three times.
Rogge, the most important man in world sport, said even he had no idea who would light the Olympic cauldron at the end of an extravaganza choreographed by Oscar-winning film director Danny Boyle.
Image: Actors perform during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London.