Ardashir I was an energetic king, responsible for the resurgence not just of Persia but of Iranian-speaking peoples as a unified nation, the strengthening of Zoroastrianism, and the establishment of a dynasty that would endure for four centuries. While his campaigns against Rome met with only limited success, he achieved more against them than the Parthians had done in many decades and prepared the way for the substantial successes his son and successor Shapur I would enjoy against the same enemy.