The first gladiator show probably took place in 264 BC, in 105 BC. the games became public and took place in the forum of Caesar. After with the Flavian dynasty, which began with the emperor Flavius Vespasian, there was the construction of the largest and most famous amphitheater in the world, the Colosseum.
In the 4th century, Emperor Constantine I, after embracing the Christian faith, prohibited them but their great popularity meant that these games continued more or less occasionally despite repeated prohibitions, especially in cities far from Rome where the last gladiator shows come to be celebrated in the early Middle Ages.

Gladiators were generally slaves, criminals sentenced to death or prisoners of war, all people who in the Roman world did not enjoy any rights and whose lives were considered expendable, while the convicts and prisoners of war, particularly fierce for having survived for years of struggles and suffering, they were much sought after.
In some cases, particularly cruel emperors sent men to death only on their whim: it is known that Claudius ordered an official to go down to the arena as he was (in toga), and that Caligula sent all the guests of a prison only because there was no meat for the animals.

Gladiators began their careers by submitting (or being sold) to the lanista. The activity of the lanista was officially considered one of the vilest in the Roman world (even below the peddlers, actors and butchers); and he had the right of life and death over the gladiators, who had to take an oath by which they committed themselves to complete submission to be accepted into the school.
The gladiator swore to "endure the whip, the mark and death by the sword"; these terrible punishments were intended to stifle any hint of rebellion and to condition the minds of the combatants so that they became convinced that their only hope of salvation was to endure any trial. The preparation lasted years, as the public had become very demanding, and only once this period was over was the gladiator ready to enter the arena.
The training took place in the so-called "Palestra", connected to the Colosseum via an underground corridor.

The categories of gladiators were: Reziari, Secutores, Mirmilloni, Traci, Dimachaeri and each category had its own peculiarities, in terms of equipment and allowed shots and its own advantages and disadvantages. The most classic fights confronted: the Reziari against the Mirmilloni or the Thracians against the Secutores.
We then competed to find always new ideas, drawing inspiration from mythological episodes, or looking for grotesque situations, such as the staged one of the emperor Domitian who, in 90 made dwarves fight against women.