The Battle of Actium was the decisive confrontation of the Final War of the Roman Republic. It was a naval engagement fought between the forces of Octavian and the combined forces of Mark Antony and Cleopatra VII. The battle took place on 2 September 31 BC, on the Ionian Sea near the city of Actium, at the Roman province of Epirus vetus in Greece. Octavian's fleet was commanded by Marcus Vipsanius Agrippa, while Antony's fleet was supported by the ships of Queen Cleopatra of Ptolemaic Egypt.
Known as the " Flavian Amphitheater" it came to be called the Colosseo because it stood on the site of the colossus of Nero, a 115 ft. tall gilded bronze statue of the emperor that once towered there. www.fodors.com