According to a contemporary Greek authority, more worthy of trust than most writers of his age and nation, the origin of the war was a refusal on the part of the Ephthalites to make certain customary payments which the Persians viewed in the light of a tribute.

Perozes determined to enforce his just rights, and marched his troops against the defaulters with this object.
But in his first operations he was unsuccessful, and after a time he thought it best to conclude the war, and content himself with taking a secret revenge upon his enemy, by means of an occult insult.

He proposed to Khush-newaz to conclude a treaty of peace, and to strengthen the compact by adding to it a matrimonial alliance.

Khush-newaz should take to wife one of his daughters, and thus unite the interests of the two reigning families.

The proposal was accepted by the Ephthalite monarch; and he readily espoused the young lady who was sent to his court apparelled as became a daughter of Persia.