The same Chinese chronicle also informs about Peroz’s son, Narseh (called in Chinese sources Ninieshi, Ninieshishi, Nihuanshi, Nilishishi, Nihuangshishi, Nimishi, or Nilishishi), who was a hostage at the Tang court. He is said to have accompanied the Chinese general Pei Xingjian in order to rescue Persia from the Arabs around 679. However, during the crossing of the Turkish territory, in nowadays Kirghizstan, the Chinese general conquered the city of Suyāb/Ak Beshim, taking the Turks and their Tibetan allies by surprise. So, Pei Xingjian left Narseh to regain the throne of Ctesiphon alone, since his true mission had been accomplished. Recent archaeological investigations at Ak Beshim confirmed some of the information in the Chinese sources (Lubo-Lesnichenko, p. 117). The true intentions of the Chinese general could be considered as accurate planning by the Tang court, because the Chinese had had diplomatic exchanges with the Arabs too at least since 651 (Petech, pp. 621-22). In fact, Narseh could never reach proper Persia and fought for twenty years against the Arabs being supported by Turkish lords of Ṭoḵārestān, like his father. A Chinese document discovered in the beginning of 20th century at Astana, near Turfan, makes mention of a so-called ‘Persian army’ (Bosi jun), which crossed the territory of Chinese Turkistan between 677 and 681 (Maspero, pp. 95-97). Possibly, this event could be identified with the passage of Narseh on his way to reestablish the Sasanian dynasty (Jiang, pp. 38-45).

After the failure of his attempt to re-conquer Persia, Narseh went back to China around 707-9, to live the rest of his days as a respected member of the Tang court, and died from a disease. The Tang emperor accorded to him the title of ‘General of the Left Majestic Guard.’ The Xin Tangshu reports (see Chavannes, p. 173; Daffinà, p. 135) that only the western part of his territory was not invaded by the Arabs (even though this looks rather enigmatic, since the Arabs were coming from the west). The same source also says that embassies coming from a country considered by the Chinese to be Persia continued to arrive at Chang’an until 755. It was proposed to recognize this country as Māzandarān or, most likely, Ṭoḵārestān, where the Arabs arrived later (Chavannes, pp. 173-4; Daffinà, p. 139; Compareti, p. 211), although at least on one occasion, an embassy reached Chang’an in 751 from a kingdom to be likely identified with Surestān in southern Mesopotamia (Daffinà, p. 138). This was actually a territory in the western part of Persia, and Mani too was said to be originally from Surestān, although on this point the Chinese sources are enigmatic (Palumbo, pp. 307-10). In the Jiu Tangshu there is a considerable confusion between the figures of Peroz and Narseh, while in the Xin Tangshu it is clearly stated that after 679 it was Narseh who fought in Ṭoḵārestān against the Arabs, as already argued by some scholars on the basis of the age of Peroz (Drake, pp. 6-7). According to Herzfeld (p. 94), Peroz was born in 636, a date which could be considered well-fitting for the general history of late Sasanians and for the events narrated in the Chinese chronicles. There then arises another question regarding the military position of Peroz as described in the Jiu Tangshu: why, in fact, should Gaozong have accorded to him two different titles?