It is the most famous amphitheatre in the world, as well as the largest, but why is it known as the Colosseum (Italian: Colosseo)?
The answer lies a few metres from the entrance to the amphitheatre in the form of a marble plaque, which marks the spot where a colossal statue once stood. Made of gilded bronze for the emperor Nero (r. 54-68), the statue was, reportedly, between 30 and 35 metres high.
It is not known (accounts vary) whether the statue depicted Nero or Sol, the Roman god of the sun. Perhaps, it depicted Nero as Sol. We may never know, but what we do know is that the statue long outlasted Nero (who committed suicide on June 9th, 68), albeit with a series of alterations to its facial features (to remove any resemblance to the emperor).
Around 128 the emperor Hadrian had the statue moved when work started on the building of the Temple of Venus and Roma, which stands to the west of the Colosseum. It took a team of 24 elephants to move the statue the short distance to its place by the amphitheatre.
It is not known when the Colossus was toppled and its bronze recycled, but at some point the Romans simply transferred its name to the adjacent amphitheatre.
It may well have been the statue and not, as was generally assumed, the amphitheatre, which was the subject of a famous 8th century prophecy, attributed (wrongly) to the Venerable Bede (673-735):
“Quandiu stat Colisaeus, stat et Roma; quando cadet Colisaeus, cadet et Roma. Quando cadet Roma, cadet et Mundus.” (While the Colossus stands, Rome shall stand; when the Colossus falls, Rome shall fall. And when Rome falls so shall the world.)