Another game was the Play of Troy, fabled to have been invented by Æneas, in which young men of rank on horses performed a sham fight. On another occasion the circus would be turned into a camp, and equestrians and infantry would give a realistic exhibition of battle. Again, there would be athletic games, running, boxing, wrestling, throwing the discus or the spear, and other exercises testing the entire physical system with much thoroughness. One day the amphitheatre would be filled with huge trees, and savage animals would be brought to be hunted down by criminals, captives, or men especially trained for the desperate work, who made it their profession. For the purposes of these combats the circus was found not to be the best, and the amphitheatre was invented by Curio for the celebration of his father's funeral games. It differed from a theatre in permitting the audience to see on both sides (Greek _amphi_, both), but the distinctive name was first applied to a structure built by Cæsar, B.C. 46. The Flavian Amphitheatre, better known as the Colosseum, of which the ruins now stand in Rome, was the culmination of this sort of building, and affords a good idea of the general arrangement of those that were not so grand. That of Cæsar was, however, of wood, which material was used in constructing theatres also; the first one of stone was not erected until 30 B.C., when Augustus was consul. [Footnote: History gives an account of one edifice of this kind made of wood that fell down owing to imperfect construction, killing many thousand spectators, and of another that was destroyed by fire. Pompey's theatre of stone, built B.C. 55, has already been mentioned (page 231).] Variety was given to the exhibitions of the amphitheatre by introducing sufficient water to float ships, and by causing the same wretched class that fought the wild beasts to represent two rival nations, and to fight until one party was actually killed, unless preserved by the clemency of the ruler. It must not be supposed that all these exhibitions were known in early times, for, in reality, they were mostly the fruit of the increased love of pleasure that characterized the close of the period of the republic, and reached their greatest extravagance only under the emperors.