This bad reputation has been attributed to the king's reputed persecution of the Zoroastrian priests and his pro-Christian sentiment. The latter probably has been exaggerated, for many of the acts of Christian martyrs from the reign of Yazdgard do not support the view that he was unduly friendly to the Christians. Perhaps his reported friendship for Marutha the bishop of Maiferqat, who was sent by the Byzantine emperor Arcadius on several embassies to Iran, changed the policy of the Sasanian ruler.
Yazdgard seems to have been ready to launch an attack on the Byzantine empire, but the embassies served the good purpose of maintaining peace, which was sealed by an agreement in the year 409. There are a number of sources about the life of Marutha, and several say he won the good graces of the Persian king by his ability as a doctor. In any case, one may conclude that the lot of the Christians in the Sasanian empire improved as a result of Marutha's influence.
It was during the reign of Yazdgard that the Christians of the Sasanian empire held a council in the city of Seleucia in the year 410. The council was convened under the patronage of Yazdgard, to use modern terms, and was composed of bishops and other ecclesiastics of the empire. They officially accepted the provisions of the Council of Nicaea. The Council of Nicaea in 325 was the first ecumenical council after the Roman emperor Constantine had accepted Christianity. At this council the heresy of Arianism was condemned. Arius, an ecclesiastic of Alexandria, had refused to recognize the divinity of Christ and his equality with God the Father. The Nicene Creed which became a statement of Christian belief declared that the Son is of "One Substance" with the Father.
In the Sasanian empire, the Christians had not formally subscribed to the decisions of the Council of Nicaea, and there had been no unanimity of opinion on the rules of the church and its organization in Iran. The Council of Seleucia changed this, for it stopped dissensions and quarrels, and created an organized hierarchy and rules for Christians in the Sasanian empire. A certain Isaac, bishop of Seleucia, became head of the church in the Sasanian empire, although he did not live long afterwards; other steps were also taken to organize the church. Towards the end of the reign of Yazdgard some Christians went too far in destroying fire temples and attacking Zoroastrian priests, whereupon they were put to death. None the less in comparison with previous rulers, Yazdgard was tolerant towards minority religions. Yazdgard is said to have married a certain Soshandukht, daughter of the resh galutha or patriarch of the Jews in the Sasanian empire, and this improved their position in the land.
An innovation in the relations between the Byzantine and Sasanian empires occurred during the reign of Yazdgard, which was the request of Arcadius that the Persian ruler act as a guardian for his young son Theodosius II. This testament has been considered merely an unimportant though polite gesture, but perhaps at the time it meant more in the eyes of the two monarchs and their subjects. Yazdgard took his charge seriously and at the death of Arcadius sent a eunuch called Antiochus to Byzantium to advise and care for the young emperor, which he did. The sons of Yazdgard, however, did not fare so well after his death. During his lifetime one son, Shapur, was sent as king of Armenia to replace the Arsacid king of Armenia, Vramshapuh, who died in 414.
Another son, Bahram, was sent to al-Mundhir, the king of the Lakhmid Arabs at Hira, to be brought up, while the existence of another son, Narseh, is implied in the sources. At the death of Yazdgard his son Shapur came from Armenia and ascended the throne. He ruled for a very short time, was killed, and a Sasanian prince from a side line, called Khusrau, was made ruler by the nobles. Bahram, however, did not accept Khusrau and moved against Ctesiphon with an army primarily of Arabs. Khusrau apparently abdicated and Bahram V became ruler in 420.
Shapur III and His Challenges
