Peroz was taken prisoner in 481 and was made to deliver his son, Kavadh, as a hostage for three years, further paying a ransom for his release.

In 484, after the liberation of his son, Peroz formed an enormous army and marched northeast to confront the Hephthalites.

Much of the Sassanid land was pillaged repeatedly for a period of two years[7] until a Persian noble from the House of Karen, Sukhra, restored some order by establishing one of Peroz's brothers, Balash, as the new king.

The Hunnic menace to Sassanid lands continued until the reign of Khosrau I. Balash failed to take adequate measures to counter the Hephthalite incursions, and after a rule of four years, he was deposed in favor of Kavadh I, his nephew and the son of Peroz.

After the death of his father, Kavadh had fled the kingdom and took refuge with his former captors, the Hephthalites, who had previously held him as a hostage.

According to Irfan Shahid, the tactic of using trenches by the Hephthalites in this war was adopted by the Persians who successfully used it later at the Battle of Thannuris (528) against the Byzantines.