By the mid-3rd century, the Lazi tribe came to dominate most of Colchis, establishing the kingdom of Lazica (or Egrisi in Georgian sources). In the 5th century, the first Christian king Gubazes I of Lazica declared Christianity as a state religion of Lazica. Locals began to have closer contact with the Greeks and acquired various Hellenic cultural traits, including in some cases the language. From 542 to 562, Lazica was a scene of the protracted rivalry between the Eastern Roman and Sassanid empires, culminating in the Lazic War. Emperor Heraclius's offensive in 628 AD brought victory over the Persians and ensured Roman predominance in Lazica until the invasion and conquest of the Caucasus by the Arabs in the second half of the 7th century.