Ardashir I's expansionist tendencies have been frustrated…

Ardashir I's expansionist tendencies have been frustrated by his failed invasions of Armenia, where a branch of the Arsacids still occupies the throne.

Given Armenia's traditional position as an ally of the Romans, Ardashir I may have seen his primary opponent not in the Armenian and Caucasian troops he has faced, but in Rome and her legions.

In 230, Ardashir leads his army into the Roman province of Mesopotamia, unsuccessfully besieging the fortress town of Nisibis.

At the same time, his cavalry ranges far enough past the Roman border to threaten Syria and Cappadocia.

It seems that the Romans see fit to attempt a diplomatic solution to the crisis, reminding the Persians of the superiority of Roman arms, but to no avail.