The Colosseum, also known as the Flavian Amphitheatre, is an oval amphitheatre in the centre of the city of Rome, Italy. Built of travertine limestone, tuff (volcanic rock), and brick-faced concrete, it was the largest amphitheatre ever built at the time and held 50,000 to 80,000 spectators. The Colosseum is just east of the Roman Forum. Construction began under the emperor Vespasian in AD 72 and was completed in AD 80 under his successor and heir, Titus. Further modifications were made during the reign of Domitian. These three emperors are known as the Flavian dynasty, and the amphitheatre was named in Latin for its association with their family name (Flavius).