During the Hellenistic period Ainos changed hands multiple times. After a spell of Macedonian rule, the city passed to Lysimachos of Thrace after the death of Alexander the Great, and was subsequently taken by the Seleucid Empire after his defeat and death at the Battle of Corupedium in 281 BC. It then became a possession of the Ptolemaic Kingdom , when it was captured as a result of the Third Syrian War around 246 BC, it was subsequently captured by Philip V of Macedon in 200 BC, and later of Antiochus the Great, who lost it to the Romans in 185 BC, whereupon the Romans declared Aenus a free city. It was still a free city in the time of Pliny the Elder.