under the rule of Persia would bring gifts to Persepolis to show their loyalty to the king and the empire. Arsacid dynasty Sassanid dynasty The Sassanid dynasty (224-651 AD) declared Zoroastrianism as the state religion and promoted a religious revival of Zoroastrianism. During the period of their centuries long suzerainty over the Caucasus, the Sassanids made attempts to promote Zoroastrianism there with considerable successes, and it was prominent in the pre-Christian Caucasus (especially modern-day Azerbaijan). Due to its ties to the Christian Roman Empire, Persia's arch-rival since Parthian times, the Sassanids were suspicious of Roman Christianity, and after the reign Constantine the Great sometimes persecuted it. The Sassanid authority clashed with their Armenian subjects in the Battle of Avarayr (451 CE), making them officially break with the Roman Church. But the Sassanids tolerated or even sometimes favored the Christianity of the Nestorian Church of Persia. The acceptance of Christianity in Georgia (Caucasian Iberia) saw the Zoroastrian religion there slowly but surely decline, but as late the 5th century AD it was still widely practised as something like a second established religion. Prophet Mani The prophet Mani was an Iranian of noble Parthian roots who established Manichaeism which contained many elements of Zoroastrianism as well as Gnosticism, however it saw the experience of life on earth by humans as miserable, which was a contrast to the Zoroastrian view which was to celebrate life through happiness. Mani was received kindly by king Shapur I and spent many years at his court where he was protected during all of Shabuhr's reign. However Mani wrote in a semitic language (Syriac Aramaic), and all his work had to be translated into Middle Persian by his followers, who rendered the name of Mani's supreme god as Zurvan and called him the father of Ohrmazd (Ahuramazda, God of Wisdom, main deity of Zoroastrianism). Zurvanism Although the origins of Zurvanite Zoroastrianism are unclear, it was during the Sassanid period that it gained widespread acceptance, and many of the Sassanid emperors were at least to some extent Zurvanites. Zurvanism enjoyed royal sanction during the Sassanid era but no traces of it remain beyond the 10th century. Unlike Mazdean Zoroastrianism, Zurvanism considered Ahura Mazda not the transcendental Creator, but one of two equal-but-opposite divinities under the supremacy of Zurvan. The central Zurvanite belief made Ahura Mazda (Middle Persian: Ohrmuzd) and Angra Mainyu (Ahriman) twin brothers that had co-existed for all