"“The driver of one was speared"

The word gladiator comes from  gladius; a term for a short sword. Gladiators were professional armed fighters, engaging other gladiators, animals and condemned criminals in order to entertain audiences. Most were slaves or convicts; but some people also volunteeered to be gladiators in order to gain fame or money or to pay off debts, although they had a legal and social status equivalent to that of slaves, were subject to infamia, and had to swear "to endure to be burned, to be bound, to be beaten, and to be killed by the sword." by their trainers, the lanistae.  Volunteers required permission from  a magistate to enter a gladiator school (ludus).   Gladiators who survived three to five years of combat were freed, and successful ones might earn large amounts of money, since they were paid every time they fought. Gladiatorial combats originated as funeral games, in which slaves fought to the death in order to appease the spirit of the deceased.  Female gladiators were occasionally known, but were prohibited by Septimius Severus in 200 A. D. Gladiators were trained in special schools owned by members of the Roman elite, and later by the emperors.  Training was probably as rigid and thorough as any in the Roman army.  The most important gladiator school was known as the Ludus Magnus. Discipline in the schools was very strict, but the gladiators were well cared for  and fed due to their high value. There was a hierarchy of grades among gladiators; the highest grade was primus palus.

Gladiators specialized with particular weapons and armour. One type of Gladiator was the "Thracian", wearing  a visored or open-faced helmet and boiled leather greaves (ocrea), and carrying a curved sword with a notch in it and a small square shield. Another type was the Secutor,  who fought virtually naked,  with a large rectangular or oval shield, leather bands, a round or high visored helmet, and  sword or dagger. The "Samnite" gladiator was equipped like the earlier Samnite warriors who fought against Rome in the late fourth and early third centuries B. C., with a visored helmet (galea), an ocrea, and a gladius. The retiarius symbolized  a fisherman and carried a net (iaculum), trident   and dagger, and wore only a loincloth and metal shoulder-piece. The Laquearius was similar to the Retiarius, but carried a lasso instead of a net.

Early gladiatorial fights usually ended in the death of one of the contestants; but in later times this became less common. Due to the high price of gladiators, it was considered a horrible disaster to lose one to death or injury. There is only one occasion on which the famous saluation "Morituri te salutant" (those about to die salute you) is recorded to have been used; in 52 A. D, by condemned prisoners about to take part in a mock naval battle on Lake Fucinus.  A defeated gladiator might appeal for mercy by raising his left hand with one finger extended, and the magistrate presiding over the games would decide whether the gladiator  lived or died; there is little evidence for the "thumbs up" and "thumbs down" signs indicating life or death. Dead gladiators were removed by costumed attendants dressed as the ferryman Charon and the god Mercury.

Pollice Verso (
Public DomainPollice Verso ("With a Turned Thumb"), an 1872 painting by Jean-Léon Gérôme, is a well known historical painter's researched conception of a gladiatorial combat

Huge amphitheatres were built for the gladiatorial games; ususally dominating the city in which they stood; the largest was the Colosseum in Rome built by Vespasian and Titus.

Gladiatorial games were extremely popular; and successful gladiators attracted  great prestige, though they were also regarded as social outcasts.  Even emperors-including Caligula, Titus, Hadrian, Lucius Verus, Commodus, Didius Julianus, Caracalla, and  Geta- competed in the games, although this was disapproved of by the Roman elite.

The last known combat between human gladiators was in 404 A. D. in the reign of the emperor Honorius. The action of the Christian monk St. Telemachus in trying to prevent a gladitorial fight, and being stoned to death by the audience, may have contributed to the demise of the sport; Gibbon described the saint as "the only monk who died a martyr in the cause of humanity".  Combats with animals, however, continued into the sixth century; after Rome had been occupied by the Ostrogoths.