AMPHITHEATRUM
a form of building that originated, apparently, in Campania, but was developed in Rome after the end of the republic. It was widely diffused throughout Italy, and has always been regarded as a distinctly Roman structure. It was intended primarily for gladiatorial contests and venationes, which had previously taken place in the forum. Around the open area of the forum temporary seats had been erected, forming an irregular ellipse. This was the reason for the shape of the amphitheatre, and for the name itself which means 'having seats on all sides.' This word, however, does not occur before the Augustan era, and was at first applied to the circus also (Dion.
Hal. iv. 44); in the inscription on the building at Pompeii (the earliest extant example) we find spectacula used(SJ 128).
The amphitheatres erected in the city of Rome itself were the following:
