 Ascending the throne at the age of eight, the young shah lacked authority and reigned as figurehead, whilst real power was in the hands of the army commanders, courtiers, and powerful members of the aristocracy, who engaged in internecine warfare.The Sasanian Empire was weakened severely by these internal conflicts, resulting in invasions by the Göktürks from the east, and Khazars from the west.It was, however, the Arabs, united under the banner of Islam, who dealt the decisive blow.