local ruler at that time. The Arabs had campaigned in Sistan a few years earlier and Abdallah b. Amir had now gone in pursuit of Yazdegerd. He arrived in Kirman in 651 and sent a force under Rabi ibn Ziyad al-Harithi to Sistan. Rabi crossed the desert between Kirman and Sistan, reaching the fortress of Zilaq which was within five farsangs of the Sistan frontier. The fort was surrendered by its dihqan. The fortress of Karkuya, whose fire temple is mentioned in the anonymously authored Tarikh-e-Sistan, along with Haysun and Nashrudh, surrendered to Rabi. Rabi then encamped in Zaliq and projected the seizure of Zarang, which though had earlier submitted to Arabs, needed to be subdued again. Although its marzban Aparviz put up a strong resistance, he was forced to surrender. The Zaranj forces had received heavy casualties during the battle with Arab forces and were driven back to the city. According to sources, when Aparviz appeared before Rabi to discuss the terms, he found the Arab general was sitting on a chair made out of two dead soldiers and his entourage had been instructed to make seats and bolsters in the same fashion. Aparviz was terrified into submission and wished to spare his people of this fate. A peace treaty was concluded with payment of heavy dues. The treaty mandated one million dirhams as annual tribute, in addition to 1,000 slave boys bearing 1,000 gold vessels. The city was also garrisoned by Rabi. Rabi thus succeeded in gaining Zarang with considerable difficulty and remained at the place for several years. Two years later, the people of Zarang rebelled and expelled Rabi's lieutenant and garrison. Abdallah b. Amir sent 'Abd ar-Rahman b. Samura to take back the city, who also added Bust and Zabul to Arab gains. 'Abd ar-Rahman besieged Zaranj and after the marzban surrendered, the tribute was doubled. The tribute imposed on Zarang was 2 million dirhams and 2,000 slaves. During the period of the first civil war in the Arab caliphate (656-661), rebels in Zarang imprisoned their governor while Arab bandits started raiding remote towns in Sistan to enslave people. They gave in to the new governor Rib'i, who took control of the city and restored law and order. 'Abdallah b. Amir was made the governor of Basra and its eastern dependencies again from 661 to 664. Samura was sent back to Sistan in 661. An expedition