 The rise of the Parthian Empire in the 3rd century BC and Rome's expansion into the Eastern Mediterranean during the 2nd century BC brought the two powers into direct contact, causing centuries of tumultuous and strained relations.Though periods of peace developed cultural and commercial exchanges, war was a constant threat.Influence over the buffer state of the Kingdom of Armenia, located to the north-east of Roman Syria, was often a central issue in the Roman-Parthian conflict.