Although the sea made serious inroads upon the territory of Dioscurias, it continued to flourish and became one of the key cities in the realm of Mithridates VI of Pontus  in the 2nd century BC and supported his cause until the end. Dioscurias issued   bronze coinage around 100 BC featuring the symbols of the Dioskuri and Dionysus. Under the Roman emperor Augustus the city assumed the name of '''Sebastopolis''' (). But its prosperity was past, and in the 1st century Pliny the Elder described the place as virtually deserted though the town still continued to exist during the times of Arrian in the 130s. The remains of towers and walls of Sebastopolis have been found underwater; on land the lowest levels so far reached by archaeologists are of the 1st and 2nd centuries AD. According to Gregory of Nyssa there were Christians in the city in the late 4th century.  In 542 the Romans evacuated the town and demolished its citadel to prevent it from being captured by Sasanian Empire. In 565, however, the emperor Justinian I restored the fort and Sebastopolis continued to remain one of the Byzantine strongholds in Colchis until being sacked by the Arab conqueror Marwan II in 736.