Following Alexander's death in 323 BC, Anatolia was subsequently divided into a number of small Hellenistic kingdoms, all of which became part of the Roman Republic by the mid-1st century BC. The process of Hellenization that began with Alexander's conquest accelerated under Roman rule, and by the early centuries of the Christian Era, the local Anatolian languages and cultures had become extinct, being largely replaced by ancient Greek language and culture. From the 1st century BC up to the 3rd century CE, large parts of modern-day Turkey were contested between the Romans and neighbouring Parthians through the frequent Roman-Parthian Wars.