Most gladiators are slaves from conquered lands. Some romans gave up their freedom to become a gladiator so they can be famous. Gladiators who gave up their freedom were taught in a gladiator school! Later some roman emperors fought as gladiators too!
The Gladius was the 27 inch short straight sword, broad towards the handle, after which the gladiator was named. The gladiators who used the gladius were those who were armed with body-shields such as the secutor, myrmillo, hoplomachus and the dimacheris.