Construction of the Colosseum began under the rule of the Emperor Vespasian[1] in around 70–72AD. The site chosen was a flat area on the floor of a low valley between the Caelian, Esquiline and Palatine Hills, through which a canalised stream ran. By the 2nd century BC the area was densely inhabited. It was devastated by the Great Fire of Rome in AD 64, following which Nero seized much of the area to add to his personal domain. He built the grandiose Domus Aurea on the site, in front of which he created an artificial lake surrounded by pavilions, gardens and porticoes. The existing Aqua Claudia aqueduct was extended to supply water to the area and the gigantic bronze Colossus of Nero was set up nearby at the entrance to the Domus Aurea.
Although the Colossus was preserved, much of the Domus Aurea was torn down. The lake was filled in and the land reused as the location for the new Flavian Amphitheatre. Gladiatorial schools and other support buildings were constructed nearby within the former grounds of the Domus Aurea. According to a reconstructed inscription found on the site, "the emperor Vespasian ordered this new amphitheatre to be erected from his general's share of the booty." This is thought to refer to the vast quantity of treasure seized by the Romans following their victory in the Great Jewish Revolt in 70AD. The Colosseum can be thus interpreted as a great triumphal monument built in the Roman tradition of celebrating great victories.[11] Vespasian's decision to build the Colosseum on the site of Nero's lake can also be seen as a populist gesture of returning to the people an area of the city which Nero had appropriated for his own use. In contrast to many other amphitheatres, which were located on the outskirts of a city, the Colosseum was constructed in the city centre; in effect, placing it both literally and symbolically at the heart of Rome.
The Colosseum had been completed up to the third story by the time of Vespasian's death in 79. The top level was finished and the building inaugurated by his son, Titus, in 80.[1] Dio Cassius recounts that over 9,000 wild animals were killed during the inaugural games of the amphitheatre. The building was remodelled further under Vespasian's younger son, the newly-designated Emperor Domitian, who constructed the hypogeum, a series of underground tunnels used to house animals and slaves. He also added a gallery to the top of the Colosseum to increase its seating capacity.
In 217, the Colosseum was badly damaged by a major fire (caused by lightning, according to Dio Cassius[12]) which destroyed the wooden upper levels of the amphitheatre's interior. It was not fully repaired until about 240 and underwent further repairs in 250 or 252 and again in 320. An inscription records the restoration of various parts of the Colosseum under Theodosius II and Valentinian III (reigned 425–450), possibly to repair damage caused by a major earthquake in 443; more work followed in 484 and 508. The arena continued to be used for contests well into the 6th century, with gladiatorial fights last mentioned around 435. Animal hunts continued until at least 523.