FORTUNE — Even before the athletes could be paid professionals who might make millions bringing home a medal, the Olympics were about money. The first modern Games, held in Athens in 1896, where nearly canceled when funds fell short — Greek businessman George Averoff saved the day by paying to restore the ancient Panathenian Stadium. Officials expected to recoup costs with ticket sales. Didn’t happen. And thus began a grand tradition of overspending to play host to the world for a fortnight.

For more on the London Summer Games, click on the links below

The (very big) bucks behind the 2012 Olympics
Wall Street gets behind the games
Henry Kissinger: Scholar, statesman, Olympic fan
Will NBC’s Olympic investment pay off?
Rich Sport: U.S. Olympic swimmers float on cash
Poor Sport: When Olympic athletes have to moonlight
London locks down for the Olympics
BMW’s ultimate Olympic machine
13 steps to keeping the London Olympics safe
London’s extreme Olympic makeover

This story is from the June 11, 2012 issue of Fortune.

*Each Olympic host country uses different methods to tally its final reckoning. many consider only public cost. Fortune’s estimates include additional private cost, legacy, and infrastructure investments.