According to Arabic-Persian sources, Ardashir started his uprising when he was the commander of Fort Darabgard in eastern Pars. The oldest archaeological proofs of the period of Ardashir's reign are acquired from Ardashir-Khwarrah (Gor or current Firuzabad) in south border of Pars. Therefore, Ardashir rose up in his war in Ardashir-Khwarrah, far from the fortress of local Persian shahs in Istakhr and farther from the Parthian Empire. The beginning of Ardashir's uprising may be related to his first inscription in Firuzabad; in the inscription, he is shown acquiring the royal ring from Ahura Mazda in front of his henchmen. Ardashir began the procedure of extending his reign by killing some local kings and taking their domains. According to Al-Tabari's report, Ardashir then asked Papak to stand against Gochihr and start a rebellion. Papak did it and rebelled against Gochihr and killed him. Daryaee believes that Papak was a local governor who dreamed of conquering Istakhr and was eventually able to achieve it by the help of his older son Shapur; that means in contrast to Al-Tabari's report, it was not Ardashir's request and order that caused Papak's rebellion against Gochihr, governor of Istakhr, and it can be implied from the common coins of Papak and Shapur. Later, Papak wrote a letter to Artabanus IV and requested permission to appoint Shapur instead of the "overthrown" Gochihr in power; in response, Artabanus announced Papak and Ardashir outlaws. Although Artabanus had defeated the Romans, he faced the problem of the defiance of Vologases VI, who had minted coins in his own name between 221 and 222; and this shows that no powerful emperor controlled the Parthian Empire then. During the time that Artabanus was dealing with a more important challenge, he could not pay much attention to the rise of a newcomer in Pars. After a while, Papak died in an unknown date and Shapur ascended to the throne; afterward, the contest and fight started between the two brothers (Shapur and Ardashir), but Shapur died in an accidental way. According to sources, Shapur stopped at a ruin while assaulting Darabgard and a stone suddenly separated from the ceiling and hit his head and Shapur succumbed immediately. After the incident, the brothers relinquished the Persian throne and crown to Ardashir, who became the Persian Shah thereafter. Ardashir and his followers could be considered the main suspects of Shapur's mysterious death, since they "benefitted from the accidental death"; but the accusation is not provable.
