Different accounts are given of his relationship to his predecessor, the native writers unanimously representing him as the son of Perozes and brother of Kobad, while the Greeks and the contemporary Armenians declare with one voice that he was Kobad's uncle and Perozes's brother.

It seems on the whole most probable that the Greeks and Armenians are right and we may suppose that Perozes, having no son whom he could trust to take his place when he quitted his capital in order to take the management of the Ephthalite war, put the regency and the guardianship of his children into the hands of his brother, Valakhesh, who thus, not unnaturally, became king when it was found that Perozes had fallen.
The first efforts of the new monarch were of necessity directed towards an arrangement with the Ephthalites, whose signal victory over Perozes had laid the north-eastern frontier of Persia open to their attack.
Balas, we are told, employed on this service the arms and arts of an officer named Sukhra or Sufraii, who was at the time governor of Seistan.

Sukhra collected an imposing force, and conducted it to the Ephthalite border, where he alarmed Khush-newaz by a display of his own skill with the bow.

He then entered into negotiations and obtained the release of Firuz-docht, of the Grand Mobed, and of the other important prisoners, together with the restoration of a large portion of the captured booty, but was probably compelled to accept on the part of his sovereign some humiliating conditions.

Procopius informs us that, in consequence of the defeat of Perozes, Persia became subject to the Ephthalites and paid them tribute for two years; and this is so probable a result, and one so likely to have been concealed by the native writers, that his authority must be regarded as outweighing the silence of Mirkhond and Tabari.