Rostam is known to have told Bahman secretly that: "if Jalinus returns to the like of his defeat, then cut off his head." The Sasanian army managed to defeat the Muslims at the Battle of the Bridge.
In 636, Yazdegerd III ordered Rostam Farrokhzad to subdue the invading Arabs and then told him: "Today you are the [most prominent] man among the Iranians.
Shahriyar was the son of Khosrau II, and was killed in 628 by his brother Kavadh II who sought to secure the throne from any rebellion.
After the death of Kavadh, a civil war began in Persia, which was fought between two factions, the Pahlav (Parthian) faction headed by the nephew of Vistahm, Farrukh Hormizd, and the Parsig (Persian) faction headed by the former Sasanian minister Piruz Khosrow.
There is no consensus over the age of Yazdegerd III when he was installed on the throne.