The Olympics first began in ancient history. Greek athletes and others from nearby areas wanted to prove who was better at certain strength events. They also wanted to do this in order to praise and worship the gods. Many gods favored athletic strength. So, these games were set up including horse racing, discuss throwing, jumping, boxing among other events. Most likely, there were gladiator games being played, so the Greeks and others were already doing athletic activities in front of a large audience already.
Then in 1896, Greece and other countries decided they wanted to have the Olympics again. The first place to hold it was in Greece and that began the Modern Olympics. Then there were other sports than the original Olympics.