Rostam Farrokhzād (Persian: رستم فرخزاد) was a dynast from the Ispahbudhan family, who served as the spahbed ("military marshal") of the northwestern quarter (kust) of Adurbadagan under the Sasanian monarchs Boran (r. 630–630, 631–632) and Yazdegerd III (r. 632–651). Rostam is remembered as a historical figure, a character in the Persian epic poem Shahnameh ("Book of Kings"), and as a touchstone of many Iranian nationalists.

Rostam was a member of the House of Ispahbudhan, one of the Seven Great Houses of Iran, which formed the elite aristocracy of the Sasanian Empire; the family traced its descent back to military marshals (spahbed), and occupied important offices in the realm. According to a romanticized legend about their origin, a daughter of the Parthian/Arsacid king Phraates IV (r. 37–2 BC), named Koshm, married a "general of all Iranians"; their offspring bore the title of "Aspahpet Pahlav", later forming the Ispahbudhan clan. Through their Arsacid lineage, the Ispahbudhan claimed to be descendants of the Kayanian kings Dara II and Esfandiyar.

Under the Sasanians, the Ispahbudhan enjoyed such a high status that they were acknowledged as "kin and partners of the Sasanians". Indeed, Rostam's father Farrukh Hormizd was the first-cousin of the Sasanian King of Kings (shahanshah) Khosrow II (r. 590–628), while his great-grandfather Shapur was the first cousin of shahanshah Khosrow I (r. 531–579). Although the hereditary homeland of the Ispahbudhan seems to have been Khorasan, the family in the course of time came to rule the northwestern quarter (kust) of Adurbadagan (not to be confused with the namesake province of Adurbadagan). Rostam's birthplace is hence reported to be in Armenia, Adurbadagan, Hamadan, or Ray. Rostam had a brother named Farrukhzad, who was active in Ctesiphon and enjoyed a great status there, reportedly being a favourite of Khosrow II.

In 602, the Byzantine emperor Maurice (r. 582–602) was murdered by his political rival Phocas. As a result, Khosrow II proceeded to declare war, ostensibly to avenge the death of Maurice. During the two decade war, Khosrow was initially successful, conquering the Roman provinces in the Near East, including Egypt. During the third phase of the war (624), however, the tables turned heavily, with the new Byzantine emperor Heraclius conquering Transcaucasia, thus leaving the northwestern Sasanian realm exposed. During this period, many Iranian grandees became dissatisfied with the rule of Khosrow II, not only due to the Byzantine victories but also his policies.

This included Rostam, who at the head of 10,000 soldiers, rebelled in the Adurbadagan province. Around the same time, Heraclius invaded Adurbadagan, sacking the city of Ganzak. The modern historian Parvaneh Pourshariati proposes two possibilities behind the success of Heraclius' invasion of Adurbadagan; one being that the significance of the rebellion allowed him to attack the province; the other being that Farrukh Hormizd stopped supporting Khosrow II, as a result allowing Heraclius to attack Adurbadagan. By 627, the distinguished Mihranid general Shahrbaraz had mutinied, while Farrukh Hormizd secretly conspired with him against Khosrow II. The following year, Khosrow II was overthrown by several powerful factions within the empire, which included; Shahrbaraz, who represented the Mihran family; the House of Ispahbudhan represented by Farrukh Hormizd and his two sons Rostam and Farrukhzad; the Armenian faction represented by Varaztirots II Bagratuni; and the Kanarang. The factions installed Khosrow II's son Kavad II on the throne, who soon had his father executed.

The fall of Khosrow II culminated in the Sasanian civil war of 628–632, with the most powerful members of the nobility gaining full autonomy and starting to create their own government. The hostilities between the Persian (Parsig) and Parthian (Pahlav) noble-families were also resumed, which broke up the wealth of the nation. A few months later, the devastating Plague of Sheroe swept through the western Sasanian provinces. Half the population, including Kavad II himself, perished. He was succeeded by his eight-year-old son, who became Ardashir III. Ardashir's ascension was supported by both the Pahlav, Parsig, and a third major faction named the Nimruzi. However, sometime in 629, the Nimruzi withdrew their support for the king, and started to conspire with Shahrbaraz to overthrow him. The Pahlav, under their leader Farrukh Hormizd, began supporting Khosrow II's daughter Boran as the new ruler of Iran, who subsequently started minting coins in the Pahlav areas of Amol, Nishapur, Gurgan and Ray. On 27 April 630, Ardashir III was killed by Shahrbaraz, who in turn was murdered, after a reign of forty days, in a coup by Farrukh Hormizd. Farrukh Hormizd then helped Boran ascend the throne, sometime in late June 630.

Boran's accession was most likely due to her being the only remaining legitimate heir of the empire able to rule, along with her sister Azarmidokht. However, she was deposed in 630, and Shapur-i Shahrvaraz, the son of Shahrbaraz and a sister of Khosrow II, was made ruler of Iran. When he was not recognized by the Parsig faction of the powerful general Piruz Khosrow, he was deposed in favor of Azarmidokht. Farrukh Hormizd, in order to strengthen his authority and create a harmonious modus vivendi between the Pahlav and Parsig families, asked Azarmidokht (who was a Parsig nominee) to marry him. Not daring to refuse, she had him killed with the aid of the Mihranid aristocrat Siyavakhsh, who was the grandson of Bahram Chobin, the famous military commander and briefly monarch of Iran. Rostam, who was at that time stationed in Khorasan, succeeded him as the leader of the Pahlav. In order to avenge his father, he left for Ctesiphon, in the words of the 9th century historian Sayf ibn Umar, "defeating every army of Azarmidokht that he met". He then defeated Siyavakhsh's forces at Ctesiphon and captured the city. Azarmidokht was shortly afterwards blinded and killed by Rostam, who restored Boran to the throne in June 631. Boran complained to him about the state of the empire, which was at that time in a state of frailty and decline. She reportedly invited him to administer its affairs, and so allowed him to assume overall power.

A settlement was reportedly made between the family of Boran and Rostam: according to Sayf, it stated that the queen should "entrust him [i.e., Rostam] with the rule for ten years,” at which point sovereignty would return "to the family of Sasan if they found any of their male offspring, and if not, then to their women". Boran deemed the agreement appropriate, and had the factions of the country summoned (including the Parsig), where she declared Rostam as both the leader of the country and its military commander. The Parsig faction agreed, with Piruz Khosrow being entrusted to administer the country alongside Rostam.