Who were the Roman gladiators?

Just as some people like watching horror movies, the Romans liked to watch people fight and kill each other. These fights took place in huge stadiums, and were watched by hundreds of people.

roman gladiators

image source: wikimedia commons

The people who fought each other to entertain the crowds were called gladiators. Gladiators were usually criminals, prisoners of war, or slaves. During the flight, if one of them was injured, he would beg for mercy. If the emperor and the watching crowd gave the thumb up sign, his life would be spared. But if they gave the thumb down sign, he would die.