traditional descriptions of Vishtaspa's ancestors as having chariots (a description that puts them fully in the Bronze Age) also contribute to the academic debate on the dating of Zoroaster; for a summary of the role of Vishtaspa's ancestors in this issue, see . In the Sistan heroic cycle Non-Zoroastrian literature in New Persian and Arabic uniformly reflects the regular development of Middle Persian wi- into gu-, with Middle Persian Wishtasp thus becoming Goshtasb in Sistan national history (Tarikh-e Sistan), Goshtasp in Firdausi's Book of Kings (Shahnameh), Goshtasf in the Mojmal al-tawarikh, Beshtashb by Al-Tabari. In several respects, for instance in Goshtasb's/Goshtasf's (etc.) mythological genealogy, the Sistan cycle texts continue the Zoroastrian tradition. So, for example, Goshtasp is identified as a member of the Kayanian dynasty, is the son of Lohrasp/Lohrasb (etc.), is the brother of Zareh/Zarer (etc.), is the father of Esfandiar/Isfandiar (etc.) and Bashutan/Beshotan (etc.), and so on. However, in the Sistan legends, Goshtasb/Goshtasf (etc.) is an abominable figure, altogether unlike the hero of Zoroastrian tradition. The reason for this discrepancy is unknown. According to the Sistan tradition, Goshtasb demands the throne from his father Lohrasp, but storms off to India ("Hind") when the king declines. Goshtasb's brother Zareh (Zareh/Zarer etc., Avestan Zairivairi) is sent to fetch him, but Goshtasb flees to "Rome" where he marries Katayoun (Katayun/Katayoun etc.), the daughter of the 'qaysar'. Goshtasb subsequently becomes a military commander for the Roman emperor, and encourages the emperor to demand tribute from Iran. Again Zareh is sent to fetch Goshtasb, who is then promised the throne, and is thus persuaded to return. Back in Sistan, Goshtasb imprisons his own son Esfandiar (Esfandiar/Isfandiar etc., Avestan Spentodata), but then has to seek Esfandiar's help in defeating Arjasp (Avestan Aurvataspa) who is threatening Balkh. Goshtasb promises Esfandiar the throne in return for his help, but when Esfandiar is successful, his father stalls and instead sends him off on another mission to suppress a rebellion in Turan. Esfandiar is again successful, and upon his return Goshtasb hedges once again and – aware of a prediction that foretells the death of Esfandiar at the hand of Rostam – sends him off on a mission in which Esfandiar is destined to die. In the Shahnameh, the nobles upbraid Goshtasb as a disgrace to the throne; his daughters denounce him as a heinous criminal; and his younger son Bashutan (Avestan Peshotanu) condemns him as a wanton