Ashtat Yeztayar was an Iranian military officer under what last great king of the Sasanian Empire, reigning from 590 to 628?
Khosrow II Khosrow II (Chosroes II in classical sources; Middle Persian: "Husrō(y)"), entitled "Aparvēz" ("The Victorious"), also Khusraw Parvēz (New Persian: خسرو پرویز ), was the last great king of the Sasanian Empire, reigning from 590 to 628.
Khosrow IV Khosrow IV was a Sasanian usurper who ruled briefly in 631. Little is known about his rule, he appears to have ruled during a time of upheaval and chaos across the Sasanian Empire the 7th century has the century where Iran has plunged into its "dark ages". He was the son of Mah-Adhur Gushnasp, who was the minister of the Sasanian Empire during the reign of Ardashir III, and Kahar-dukht, the daughter of Yazdandar, who was the son of Khosrau I. His rule seems to coincide with other pretenders such as Hormizd VI so it is likely that he ruled a district or province rather than the Empire in its entirety. He was killed after a few days of reign.