General Notes

Kavadh I proved himself a vigorous ruler. He restored peace and order in the land. A campaign against the Romans (502) resulted in the destruction of Amida, but another inroad by the Hephthalites in the east compelled him to ratify a peace treaty with the Byzantines.

Toward the close of his reign, in 527, he resumed the war and defeated the Byzantine general Belisarius at Callinicum (531) with the support of al-Mundhir II of al-Hirah. Earlier in his reign he had moved away from the Zoroastrian church and favoured Mazdak, the founder of a new socio-religious movement that had found support among the people. The crown prince, Khosrow, however, was an orthodox Zoroastrian; toward the end of his father's reign, in collaboration with the chief mobed, he contrived the condemnation of the Mazdakites, who were destroyed in a great massacre (528).
Source: www.eb.com