1. The first Olympic Games took place in ancient Greece in the eighth century before Christ. They continued until the early fourth century AD, when they were suppressed by the newly Christian Roman empire. The games were part of a pagan tradition: a major cultural, political and religious event in Greece, dedicated to Zeus, king of the gods. Mount Olympus was the home of the gods.
2. Any wars among the ancient Greeks were suspended while the Games were on, but the event was also used by some leaders to announce new political alliances and deals.
3. The earliest Games comprised foot races. Sports such as boxing, wrestling and javelin throwing were added later. In the fighting events, there was no time limit – the fight continued until one contestant surrendered. If an athlete killed his opponent, the dead man was immediately declared the winner.
4. Today, just more than 30 sports are represented, in about 400 events. About 13 000 athletes from 300 nations take part.
5. This year's summer Olympics take place in London from July 27 to August 12. The winter Olympics follow in 2014. They will take place in Sochi, Russia.
6. South Africa's "blade runner", Oscar Pistorius, was included in the country's team at the last minute after some indecision about whether a runner with carbon-fibre blades instead of legs from the knee down was eligible. He will run in the 400m race and the 1600m relay. He will also participate in the Paralympics, starting later in August.
7. South Africa will take 125 track and field athletes to the Games this year.
8. The modern Olympic movement was founded by the Baron de Coubertin in 1894. A writer on history and education, he believed that "organised sport can create moral and social strength". The first modern Games were held in Athens in 1896.
9. The ancient Games were open to any free-born men who spoke Greek. Athletes competed naked. It is not clear how she got away with it, but there is a legend that a woman named Bilistiche competed one year and emerged a winner.
10. Runner Caster Semenya will be the official flag-bearer of the South African team at the opening ceremony.