Nicopolis Actia, city about 4 miles (6 km) north of Préveza, northwestern Greece, opposite Actium (now Áktion) at the mouth of the Ambracian Gulf (now Amvrakikós Gulf). It was founded in 31 bc by Octavian (who in 27 bc was to become the Roman emperor Augustus) in commemoration of his victory over Antony and Cleopatra at Actium. Nicopolis Actia became the capital and economic heart of the new province of Epirus, which encompassed Acarnania and southern Epirus (now Ípiros).