The Romans built the Colosseum to hold gladiatorial games, they built the Circus Maximus to hold chariot races, but they never built a proper zoo. The Romans didn’t want to watch the beasts in a peaceful environment; they wanted to watch them in the act of killing or being killed. In the Empire’s later period, spectacles featuring beasts and gladiators were being held for half of the days of the year. Every year traders brought thousands of beasts from the Middle East and Africa to be slaughtered for mass entertainment in Rome: rhinoceros, hippopotamuses, elephants, bulls, hyenas, giraffes, lions, panthers, leopards, bears, tigers, crocodiles and ostriches.
Commenting on Roman Gladiator sports, historian W. E. H. Lecky writes: “Four hundred bears were killed in a single day under Caligula… Under Nero, four hundred tigers fought with bulls and elephants. In a single day, at the dedication of the Colosseum by Titus, five thousand animals perished. Under Trajan… lions, tigers, elephants, rhinoceroses, hippopotami, giraffes, bulls, stags, even crocodiles and serpents were employed to give novelty to the spectacle.” In another passage, Lecky writes: “It is related of Claudius that his special delight at the gladiatorial shows was in watching the countenances of the dying; for he had learnt to take an artistic pleasure in observing the variations of their agony.”
In 107 AD, Emperor Trajan celebrated his victories in Dalcia by hosting a three month gladiatorial festival at the Colosseum. About 11000 gladiators (slaves and criminals) were killed in this festival. Around the same number of animals were killed. The festival attracted five million spectators during the course of three months. In another gladiator show 32 elephants, 10 elk, 20 mules, 10 tigers, 40 horses, 60 lions, 30 leopards, 10 hyenas, 10 giraffes, 6 hippos, a rhino, and several dozen gazelles and ostriches were slaughtered in a single day.
The bloodbath at gladiatorial games and chariot races went on for centuries with hardly any protest. Why didn’t the Romans build a proper zoo? One reason could be that they were a warlike culture. Some historians have argued that the Roman emperors were trying to sustain the military spirit of the Empire by giving the populace the opportunity to watch the slaughter of men and beasts in gladiator shows. But this argument does not stand up—because there is no dearth of warlike cultures which never held gladiator sports and have built proper zoos and gardens.
The ancient Egyptian capital of Hierakonpolis had a zoo in 3500 BC. King Solomon of the Kingdom of Israel and Judah had collected several animals for his zoo. The Babylonian Kings built the Hanging Gardens of Babylon in the sixth century BC. All major rulers in Ancient India have built gardens which held a variety of plants and animals. The Chinese Emperors have been building zoos since the ancient period. The Persian Empire had zoos and gardens in most of its cities (including Babylon). During his conquest of Persia, Alexander the Great was impressed by the Persian zoos and gardens, and he sent several animals to Greece.
The Circus Maximus, where the Romans held their chariot races, was designed to maximize collisions. The racing track would narrow suddenly after the sharp turns and this increased the likelihood of collisions between the chariots racing each other neck to neck. The collisions were often fatal. Most charioteers died not in the collision but from being dragged around the track after the collision. This is because the charioteers used to tie their arms to the reins. The Circus Maximus often became the venue for beast hunts—gladiators in chariots used to race after the beasts and slaughter them on the racing track.
The bloodiest Roman gladiator sport was the naumachia which featured naval battles for mass entertainment. The first naumachia was organized by Julius Caesar in 46 BC. He made 2000 warriors and 4000 oarsmen (all of them prisoners of war) fight a naval battle in a basin dug near the Tiber river. Most of Rome's population came out to watch 6000 people fighting to death. The largest naumachia was organized by Emperor Claudius in 59 AD, on a natural body of water, the Fucine Lake. 19000 combatants (all of them prisoners) were put in 100 ships and made to fight. Roman historian Tacitus said: “After much blood had flowed, the survivors were spared.”