Bahram III gained his title of "sākān shāh" presumably after his father's victory over the Sakastan (present day Sistan) region.

Also following early Sasanian practices of giving appanage of provinces to princes, Bahram III was appointed to Sakastan, a region of strategic importance in defending the eastern extremes of the kingdom.

He was still a minor at the time of his ascension, and many nobles (outside his core group of supporters) considered him too weak to properly handle the threat posed by the Romans and the possibility of invasion.

They decided to challenge his succession to the throne and instead pledged allegiance to Narseh, the last remaining son of Shapur I, perceived as being a stronger leader and better able to bring glory to Iran.

The reasons behind the nobles favour of Narseh might have been due to his jurisdiction as governor, his image as an advocate of the Zoroastrian religion and as an insurer for harmony and prosperity of the empire.

It is believed that he is depicted wearing a gold crown with a crenellated lower rim and two large deer horns or at least replicas of them attached on each side.