The Rise of Laz Kingdom
Along with the rest of Colchis, the territory of modern-day Abkhazia was conquered by Mithridates VI Eupator of Pontus between c. 110 and 63 BC, and then taken by the Roman commander Pompey. With the downfall of the Roman Empire, the Colchian tribes living in the region gained some independence, nominating their rulers who were to be confirmed by Rome.
In the 3rd century AD, the western Georgian tribe of Lazoi (Lazs) came to dominate most of Colchis, establishing the second Georgian tribal union known as kingdom of Lazica, locally called Egrisi. According to Procopius, the Abasgoi chieftains were also subdued by the Lazic kings. This kingdom was a scene of the protracted rivalry between the Eastern Roman/Byzantine and Sassanid empires, culminating in the well-known Lazic War from 542 to 562 AD. The war resulted in the decline of Lazica, and the Abasgoi in their dense forests won a degree of autonomy under the Byzantine authority. Their land, known to the Byzantines as Abasgia, was a prime source of eunuchs for the empire, and pagan until a mission sent by the emperor Justinian I (527-565) converted the people in Christianity, though at the 325 Council of Nicaea a bishop had attended from the port city of Pityus.