Naval Battles at the Colosseum: The Naumachiae
It sounds too strange to be true: the Colosseum, flooded with water, with real ships fighting inside it. But ancient writers insist it happened. These staged sea battles were called naumachiae, and they were among the most extraordinary — and short-lived — spectacles the arena ever staged.
Want to see where it happened? The engineering behind the flooding and the underground that ended it is best seen on the arena floor and underground tour. Check underground & arena tours →
What were the naumachiae?
A naumachia was a mock naval battle staged as public entertainment. The Romans re-enacted famous historical sea fights using real, shallow-draught boats and crews — frequently prisoners or the condemned — who fought in earnest. The earliest versions predate the Colosseum and used flooded basins, but ancient sources describe the new amphitheatre itself being flooded for the spectacle during its inaugural games in AD 80.
How did the Romans flood the Colosseum?
This is where Roman hydraulic engineering shows off. Water was channelled in from the city's aqueduct network to fill the arena, then drained away afterward. In the building's first years, before the floor was undercut by tunnels, the arena could briefly be made watertight enough to float small ships. Whether the water was deep is debated, but the capability to flood and drain the space is well attested.
Stand on the arena floor and the scale of pulling this off becomes obvious.
See arena & underground tickets →Why the naval battles stopped
The naumachiae had a built-in expiry date. When the emperor Domitian added the hypogeum — the two-level maze of tunnels, cells and lifts beneath the arena — the floor could no longer be sealed and flooded. The Romans traded one marvel for another: they gave up the sea battles to gain the trapdoors and elevators that made beasts and gladiators appear from below. Few stories show so vividly how the Colosseum's architecture and its spectacles kept rewriting one another.
FAQ
Did the Colosseum really host naval battles?
Yes. Ancient sources, including Suetonius and Cassius Dio, describe the Colosseum being flooded to stage mock naval battles called naumachiae during its earliest years, around the inaugural games of AD 80 under the emperor Titus. Smaller, shallow-draught boats re-enacted famous sea fights for the crowd.
What is a naumachia?
A naumachia was a staged naval battle put on as Roman public entertainment. Crews — often prisoners or the condemned — fought re-enactments of historic sea battles in a flooded arena or a purpose-built basin, complete with real ships, ramming and casualties.
How was the Colosseum flooded?
The arena was flooded using water channelled from Rome’s aqueduct network into the amphitheatre, with a system to fill and then drain it. Because the floor sat above a sealed sub-structure at first, it could briefly hold water — a feat of Roman hydraulic engineering.
Why did the Colosseum stop hosting naval battles?
The naval battles ended once the underground hypogeum was built beneath the arena floor under the emperor Domitian. The network of tunnels and lift shafts made it impossible to seal and flood the arena, so the spectacle was abandoned in favour of the trapdoor-driven shows the hypogeum enabled.