An informative website
...sort of
Throughout Roman history, Lions have been very popular among colosseum matches where they would face a gladiator.
Such lions have also been used as death sentences to punish martyrs or traitors to the empire. Click here to learn more about sacrificing Christians to the lions in Ancient Rome.
The main concept the Romans had in mind when making gladiators fight against lions however, was to show that man was better than animals and
that the animal was at the mercy of the Roman Empire.
The Romans did not do the catch the Lions themselves, they simply traded with African tradesmen to bring the exotic creatures. It was usually the Africans that were left to the did the difficult job of capturing lions. Once captured and traded, Romans would take the animals to the Beast Master of the Colosseum.