As tradition continues, under the reign of King Valax (identified with a Vologases of the Arsacid Dynasty), an attempt was made to restore what was considered the Avesta. During the Sassanid Empire, Ardeshir ordered Tansar, his high priest, to finish the work that King Valax had started. Shapur I sent priests to locate the scientific text portions of the Avesta that were in the possession of the Greeks. Under Shapur II, Arderbad Mahrespandand revised the canon to ensure its orthodox character, while under Khosrow I, the Avesta was translated into Pahlavi.