 The governors of the provinces of Mazun and Yemen had already asserted their independence during the civil war of 628–632, thus resulting in the disintegration of Sasanian rule in the Arabian peninsula, which was uniting under the banner of Islam.The empire was starting to look more like the Parthian feudal system before the fall of the Arsacid Empire.Yazdegerd, although being acknowledged as the rightful monarch by both the "Parsig" and "Pahlav" factions, does not seem to have held sway over all of his empire.