How Was the Roman Colosseum Built?

The Roman Colosseum was constructed using a combination of innovative engineering techniques and a variety of materials, reflecting the architectural prowess of ancient Rome. The construction of the Colosseum began under Emperor Vespasian between 70 and 72 ce. The site chosen for the Colosseum had a symbolic significance, replacing Emperor Nero’s private lake with a public amphitheater. The foundation was laid using concrete. The main structural framework and facade were made of travertine, while the secondary walls were constructed from volcanic tufa. The inner bowl and arcade vaults were also made of concrete, showcasing the Romans’ advanced use of the material.

The Colosseum was designed as a freestanding structure, unlike earlier amphitheaters that were typically built into hillsides for support. It featured a complex system of barrel vaults and groin vaults, which allowed it to rise to a height of four stories. The exterior was adorned with three levels of arcades, each framed by columns in the Doric, Ionic, and Corinthian orders, respectively. This arrangement of columns later influenced Renaissance architecture. The Colosseum’s oval shape measured 620 feet by 513 feet (189 meters by 156 meters), with a seating capacity of around 50,000 spectators.

The construction of the Colosseum was funded by the spoils from the sack of Jerusalem in 70 ce and was largely built by enslaved Jews from Judaea. The Colosseum was officially dedicated in 80 ce by Emperor Titus, Vespasian’s son, with a grand ceremony that included 100 days of games. The fourth story was added by Emperor Domitian in 82 ce, completing the structure.