The question of Shahnama of Ferdowsi as a historical text has been a persistent one since the invention of Shahnama studies as a modern discipline (arguably by Theodor Nöldeke’s monumental das iranische Nationalepos). While many insist on the importance of the person of Ferdowsi as a historian himself, the general consensus of most Shahnama scholars, particularly the Iranian ones, is that the sources of the Shahnama were in fact written and that Ferdowsi was basing his poem on a recorded and prepared text (see here for a discussion by Dick Davis, as well as the opposite views of Olga Davidson and Mahmood Omidsalar, the latter of which reflects a common take among Iranian scholars of the Shahnama).
The main concentration, of course, is on the general historical framework of the Shahnama, what I call an Orientalist-imposed tripartite the division of the Shahnama. This is basically divided alongside the dynastic divisions, with the Pishdadi dynasty from Gayumarth to Zab representing the Mythological section, the Kayanids from Kay Qubad to Daray-e Darayan representing the Epic section, and the short section on the Arsacids and the much longer section on the Sasanians being deemed Historical. This division was first proposed by Nöldeke and is almost canonical in Shahnama studies. I disagree with this division strongly, as I believe that much like the similar narratives in many other Islamic sources, for Ferdowsi himself, and his sources, all three (four?) dynasties were historical indeed. I will, however, not dwell on it much here as that would require a whole different essay.
I have suggested elsewhere that Ferdowsi’s role as a historian is really most significant when it comes to local history of East Iran/Khurasan, essentially the geographical space in which he was active. This geography also is also intertwined with the historical space that Ferdowsi occupied, namely the Samanid-Ghaznavid transition, as Ghazzal Dabiri has already pointed out. But we seem to ignore most of this local historical and geographical context because of interest in the larger “universal” history of pre-Islamic Iran which is indeed the focus of Ferdowsi.
In fact, a feature of Persian historiography as a while is this focus on geography, concentrating on local and regional history and gazing at the larger “universal” history – the Iranian National History as Ehsan Yarshater puts it – from the point of view of the local. This geographical gaze of pre-Mongol Persian historiography is not something that I have seen pointed out too often, even in works such as Julie Scott Meisami’s Persian Historiography. Despite concentration on the question of “Why Write History in Persian?”, considering the relation between Persian and power in the Samanid, Ghaznavid, and Seljuq courts, the geographical aspect seems not to be of much concern when looking for whens and whys of Persian historiography. This is probably because historiography per se is supposed to have a clear indication of political power and claim to universality.
What is thus neglected is taking note of regional historiographies, written often by anonymous authors (eg Tarikh-e Sistan) where the geographical space becomes the main actor. Apart from Tarikh-e Sistan, the Farsnama of Ibn Balkhi is an excellent example of this. But this even pre-dates writing in Persian, as the original – and now lost – Arabic versions of the History of Bukhara and the History of Qom demonstrate. One could argue that the Iranian tradition of historiography was itself largely regional and started as an expression of regional histories. I have made this argument for the case of the Sasanian section of the history of al-Tabari as well and shall expand on it later. But this can even be seen in the historical segments of Middle Persian texts.
So, I think Ferdowsi too should be seen as a local historiographer. The location of Tous, Ferdowsi’s native city, at the heart of Samanid and Ghaznavid Khurasan, makes this quite natural, although today’s political borders render it a peripheral town on the extreme north-east of Iran. As mentioned before, Ferdowsi’s information about certain local events, including the Battle of Bukhara between the Western Turk and the Hephthalite forces, is unparalleled and not repeated elsewhere. Farzin Ghaffouri’s work on the sources of the Shahnama for the reign of Khosrow I Anusheruwan also points out this local aspect.

An example of this, which might be worth mentioning, is the entire historiography of Rostam. The possible historical origins of Rostam have occupied the pages of many books and journals (see here for ADH Bivar’s famous, and quite influential, take). But Ferdowsi himself, or at least in a verse attributed to him, says that “Rostam was a hero in Sistan/I am the one who made him the hero of stories” (my loose translation). So, for Ferdowsi, Rostam was a real hero from Sistan, made into an almost mythological character in Ferdowsi’s tale. Of course, Ferdowsi did not make up Rostam, nor was the man unknown as is obvious from his mural from Panjikent hundreds of years before Ferdowsi.

He also was well known in the late Sasanian period, as we can see from the name of Rostam-e Farrokhzad, the Sasanian general who commanded the Sasanian forces against the Muslim troops of Sa’ad b. abi-Waqqas at the Battle of Qadisiyya. The name is also a common one among the post-Sasanian rulers of the region of Padishkhwargar (the southern Caspian coast), including the Bavandid and Qarinvand ispahbeds of Tabarestan, as well as various Daylamite warlords.
So Ferdowsi’s statement about Rostam being a “hero in Sistan” seems to be an interesting case of history moving toward mythology. The association of Rostam with Sistan and Zawulistan obviously pre-dates Ferdowsi, as is shown, again, by the Panjikent mural. It was already pointed out by Frantz Grenet that the head of Rostam in the mural looks very much like the portrait of the Alkhan kings of S. Hindukush and Gandhara region such as Khingila. I discussed this further in the epilogue of my book and posited that this might in fact reflect the contemporary politics of the Seventh century, when the mural was produced. This means that the artist of the mural in fact associated Zabulistan with its contemporary rulers, the issuing authorities of the Alkhan-Nezak crossover coins (see Klaus Vondrovec’s volumes for a deep discussion of these), and thus modelled Rostam on these kings.


So, for the artist of the Panjikent mural, as well as for Ferdowsi, Rostam indeed was a Zabulistani/Sistani hero (explanation here: Sistan and Zabulistan are often juxtaposed and presumed to be the same in the Shahnama). So, Ferdowsi’s inclusion of the stories of Rostam across most of the earlier parts of the Shahnama – indeed he straddles both the so-called Mythological and Epic sections – is in fact his own historiographical contribution. This weaving of the stories of the hero of Sistan/Zabulistan (see Saghi Gazerani’s work on this, although I disagree with many of her takes) is thus a way of “localising” history by Ferdowsi. Alongside other tales such as the Western Turk vs. Hephthalites war or the story of Wahram Chobin (perhaps relying on the same local work that Bal’ami had used earlier), these accounts bring a particularly regional flavour to Ferdowsi’s historiography. This, in my opinion, renders him indeed a historian – at least as much as Bal’ami was one beside being a translator of al-Tabari – who can also be credited with authorship, although not the sort of historian that was imagined before.