with the local potentates often rebelling and appealing to outside powers like the Hepthalites, Western Turks or Turgesh, Sogdians and the imperial Chinese who claimed a degree of suzerainty over Central Asia, for help. Within a year after Yazdegerd's death, a local Iranian notable named Qarin started a revolt against the Arabs in Quhistan. He gathered his supporters from Tabasayn, Herat and Badghis, assembling a reported army of 40,000 insurgents against Arabs in Khorasan. The Arabs made a surprise attack however, killing him and many of his people while many others were taken captive. It was expected that the recently subjugated people would revolt. However, in Khorasan, no all-out effort seems to have been undertaken to the expel the Arabs after Qarin's rebellion. Chinese sources state that there was an attempt to restore Peroz by Tokharistan's army, however this episode is not confirmed by Arab sources. Peroz had settled among the Turks, took a local wife and had received troops from the king of Tokharistan. In 661, he established himself as king of Po-szu (Persia) with Chinese help in a place the Chinese called Ja-ling (Chi-ling), which is assumed to be Zarang. His campaigns are reflected in Muslim sources, which mention revolts in Zarang, Balkh, Badghis, Herat, Bushanj and also in Khorasan during the First Fitna period in reigns of Ali and Muawiyah. Though they do not mention Peroz, they do state that Ali's newly appointed governor of Khorasan had heard in Nishapur that governors of the Sasanian king had come back from Kabul and Khorasan had rebelled. However, the region was reconquered under Muawiyah. Piroz went back to the Tang Empire's capital and was given a grandiose title as well as permission to build a fire temple in 677. Yazid ibn al-Muhallab succeeded his father as governor of Khorasan in 702 and campaigned in Central Asia, but achieved little success apart from Nezak Tarkhan's submission at Badghis. Tokharistan Tokharistan, roughly ancient Bactria, is today divided between Afghanistan, Tajikistan and Uzbekistan. According to the most general usage of the name, Tokharistan is the wide valley around the upper Oxus river surrounded by mountains on three sides before the river moves into open plains. The major city was Balkh, one of the greatest urban centers of northeastern Iran. It was located upon crossroads and conduits of trade in many directions, enabling control of these routes if it was conquered. During the