Battle of Herat ( 484 ) The Battle of Herat was a large scale military confrontation that took place in the year 484 . The battle was fought between an invading force of the Sassanid Empire composed of around 100 , 000 men under the command of Peroz I and a smaller army of the Hephthalite Empire ( AKA the " White Nomads " ) under the command of Khush - Newaz . The battle was a catastrophic defeat for the Sassanid forces who were almost completely wiped out . Sassanid King Peroz I was killed in the action . Context . In 459 , the Hephthalite Empire occupied Bactria and were confronted by the forces of the Sassanid king , Hormizd III . It was then that Peroz I , in an apparent pact with the Hephthalites , killed Hormizd , his brother , and established himself as the new king . He would go on to kill the majority of his family and began a persecution of various Christian sects in his territories . Peroz I quickly moved to maintain peaceful relations with the Byzantine Empire to the west . To the east , he attempted to check the Hephthalite expansion whose armies had began their conquest of eastern Iran . The Romans supported the Sassanids in these efforts , sending them auxiliary units . The efforts to deter the Hephthalite expansion met with failure when Peroz I chased their forces deep into Hephthalite territory and was surrounded . Peroz I was taken prisoner in 481 and was made to deliver his son , Kavadh I as a hostage for three years , further paying a ransom for his release . It was this humiliating defeat which led Peroz I to launch a new campaign against the Hephthalites . The Battle . In 484 , after the liberation of his son , Peroz I formed an enormous army and marched northeast to confront the Hephthalites . The king marched his forces all the way to Balkh where he established his base camp and rejected emissaries from the Hunnic king Khush - Newaz . Peroz I ' s forces advanced from Balkh to Herat . The Huns , learning of Peroz I ' s way of advance , left troops along his path who proceeded to cut off the eventual Sassanid retreat and surround Peroz ' army in the desert around the city of Herat . In the ensuing battle , almost all of the Sassanid army was wiped out . Peroz I was killed in the action and most of his commanders and entourage were captured including two of his daughters . The Hephthalite forces proceeded to sack Herat before continuing on to a general invasion of the Sassanid Empire . Aftermath . The Huns invaded the Sassanid territories which had been left without a central government following the death of the king . Much of the Sassanid land was pillaged repeatedly for a period of two years until a Persia n noble from the House of Karen , Zarmihr ( AKA Sokhra ) restored some order by establishing one of Peroz I ' s brothers , Balash I , as the new king . The Hunnic menace to Sassanid landswould continue until the reign of Khosrau I . Balash I failed to take adequate measures to counter the Hephthalite incursions , and after a rule of four years , Balash I was deposed in favor of Kavadh I , his nephew and the son of Peroz I . After the death of his father , Kavadh I fled the kingdom and took refuge with his former captors , the Hephthalites , who had previously held him as a hostage . He there married one of the daughters of the Hunnic king who gave him an army to conquer his old kingdom and take the throne . The Sassanids were made to pay tributes to the Hephthalite Empire until 496 when Kavadh I was defeated in battle by Mazdak and forced to flee once again to Hephthalite territory . King Djamasp was installed on the throne for two years until Kavadh I returned at the head of an army of 30 , 000 troops and retook his throne , reigning from 498 until his death in 531 when he was succeeded by his son Khosrau I .