The new Sassanid Empire which he founded enforced the restored religion of Zoroaster (Zarathustra) on the whole of Iran.
The Sassanid kings of Persia ruled a dominion which extended from the confines of Syria to those of India, and from the straits of Oman to the Caucasus.
His father Anak, head of the Parthian clan of Suren, was bribed about the time of his birth (c. 257) by the Sassanid king of Persia to assassinate the Armenian king, Chosroes, who was of the old Arsacid dynasty, and father of Tiridates or Trdat, first Christian king of Armenia.
The Sassanid ruler is the representative of the Kingly Majesty, derived from Ormuzd, which appears in the Avesla as the angel Kavaem Hvareno, the royal glory, and, according to legend, once beamed in the Iranian kings, unattainable to all but those of royal blood.
The period, from the death of Alexander to the Sassanid Ardashir I., is put by the Persian tradition at 266 years; which was afterwards corrected, after Syro-Grecian evidence, to 523 years.
Gregory persuaded Tiridates to destroy the last relics of the old paganism, and carried out in the religious sphere his sovereign's policy of detaching Great Armenia from the Sassanid realm and allying it with the GraecoRoman empire and civilization.
It was borne by several dynasts of Persis, when it formed an independent kingdom in the time of the Parthian empire (on their coins they call themselves Artakhshathr; one of them is mentioned by Lucian, Macrobii, 15), and by three kings of the Sassanid dynasty, who are better known under the modern form Ardashir.
In Firdousi, the legendary princes are followed, almost without a break, by Ardashir, the founder of the Sassanid dynasty: the intervening episode of Darius and Alexander is not drawn from native tradition, but borrowed from Greek literature (the Alexander-romance of the Pseudo-Callisthenes) in precisely the same way as among the nations of the Christian East in the middle ages.i Needless to say, however, this long period saw the Saga much recast and expanded.
The Sassanid Empire, indeed, is completely dominated by this formalism and ritualism; but the earlier testimony of Darius in his inscriptions and the statements in Herodotus enable us still to recognize the original healthy life of a religion capable of awakening the enthusiastic devotion of the inner man.
In later times, before the foundation of the Sassanid dominion, Penis was disintegrated into numerous small local states.