YAZDEGERD ("made by God," Izdegerdes), the name of three Sassanid kings of Persia, (i) YAZDEGERD I., son of Shapur III., 399-420, called " the sinner " by the Persians, was a highly intelligent ruler, who tried to emancipate himself from the dominion of the magnates and the Magian priests. He punished the nobles severely when they attempted oppression; he stopped the persecution of the Christians and granted them their own organization. With the Roman Empire he lived in peace and friendship, and is therefore as much praised by the Byzantine authors (Procop. Pers. i. 2; Agath. iv. 26) as he is blamed by the Persians. After a reign of twenty years he appears to have been murdered in Khorasan.
(2) YAZDEGERD II., was the son of Bahrain V. Gor, 438-457. He persecuted the Christians and Jews, and had a short war with Rome in 441. He tried to extend his kingdom in the East and fought against the Kushans and Kidarites (or Huns).
(3) YAZDEGERD III., a grandson of Chosroes II., who had been murdered by his son Kavadh II. in 628, was raised to the throne in 632 after a series of internal conflicts. He was a mere child and never really ruled; in his first year the Arabic invasion began, and in 637 the battle of Kadisiya decided the fate of the empire. Ctesiphon was occupied by the Arabs, and the king fled into Media. Yazdegerd fled from one district to another, till at last he was murdered at Merv in 651 (see CALI- PHATE, sect. A. i). The Parsees, who use the old Persian calendar, continue to count the years from his accession (era of Yazdegerd, beginning June i6th, A.D. 632). (Eo. M.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)