A BBC cameraman films the opening ceremony of the 1948 Olympic Games at Wembley Stadium. (Photo from the BBC Archive.)

One billion TV viewers from all over the globe are expected to watch the opening ceremony of the Olympic Games in London. It takes place on Friday, rain or shine.

The show is expected to feature 20,000 performers, a cavalcade of farmyard animals and some sophisticated digital technology. But in the summer of 1948, the last time London hosted the Olympics, things weren't quite so fancy in London's old Wembley Stadium.

"One by one the teams marched in," said Janie Hampton, a historian of the games and author of "London Olympics, 1908 and 1948."

The teams then lined up in front of King George VI, the father of the Queen Elizabeth II, and the subject of the movie "The King's Speech." King George proclaimed the games open and "a single torch bearer ran in; they sang 'God save the King; they let 7,000 pigeons go; and that was it," Hampton said.

The 1948 Games were the first big celebration since the end of World War II.

"There was just this wonderful feeling of 'hooray, we're at peace, we can just enjoy ourselves running and jumping and rowing,'" Hampton said.

The celebratory pigeons weren't quite so happy. They were kept in boxes, waiting for the big release. On the day of the opening ceremony, a heatwave struck. Only half of the pigeons flew away because the other half were dead.

They were the make-do games. Much like today, they took place in a time of austerity. After six years of war, there wasn't much in Britain to go around.

Everyday goods, including food, were strictly rationed. A British adult was allowed to eat 2,500 calories a day, including one egg a week. But British Olympians got more: extra bread, more eggs. They were allowed the same caloric intake as a coal miner.

Much of the food was donated from countries including the Netherlands and Czechoslovakia. Everyone pitched in and made a virtue of the situation.

The science of sports nutrition took off at the 1948 Games too. Magnus Pyke, a British government nutritionist, took samples from the world's athletes. He learned — among other things — that the Mexican diet of tripe, chili and beans did not necessarily translate into medal-winning performances.

The late Bob Mathias, a U.S. Congressman from California, was just 17 when he competed in the decathlon in 1948. He recalled the javelin portion going late into the evening — and a lack of illumination at the center of the field.

"I remember the English officials had their flashlights that they actually shone on the foul marker," he said. "And once you threw the javelin it'd disappear in the darkness. Then all of a sudden you'd hear it thud at the other end and see a bunch of flashlights running out to where the javelin stuck."

Mathias won gold in London. He and the rest of the American team faced competition from just 58 other countries. More than 200 nations are taking part this year.

Contemporary Olympic Games are massive, complex enterprises. For the organizers there can be no muddling through or making do, only grand achievement or failure. Still certain notions persist, such as a warm welcome.

In 1948, British Prime Minister Clement Attlee broadcast a message on the eve of the games.

"We wish to do all we can to make the visits of our friends from other countries as happy as possible," he said. "Here, then, are all good wishes to competitors and spectators alike for a successful Olympic Games."

That down-to-earth tone will likely be in evidence on Friday at the opening ceremony. London in 2012 isn't able to spend on showmanship what Beijing did four years ago. Perhaps the lesson of 1948 is that it doesn't need to.

The opening ceremonies will be at 9 p.m. in the United Kingdom, 4 p.m. ET, 3 p.m. CT in the United States. The opening ceremony will be shown tape-delayed on NBC in prime time.