Vespasian built the Colosseum, formally known in antiquity as the Flavian Amphitheatre.
Construction began around 72 CE under Emperor Vespasian, founder of the Flavian dynasty. The amphitheatre occupied land associated with Nero’s enormous palace complex, the Domus Aurea. Reusing that central site helped the Flavians present themselves as rulers returning public space to the Roman people.
Vespasian died in 79 CE before the building was finished. His son Titus inaugurated it in 80 CE with elaborate games, and Domitian later completed or expanded parts of the complex. The arena could host gladiatorial contests, animal hunts, executions, and other spectacles.
The name “Colosseum” became common later, probably because of the colossal statue of Nero that once stood nearby. It was not named after a Roman emperor called Colosseus. The Flavian dynasty ruled from 69 to 96 CE.