and Pushang for a tribute of 1 million dirhams. The ruler who was known as azim or the "mighty one" in Futuh al-Buldan, may have been a Hepthalite chief. The Rashidun Caliphs followed the earlier rule of Muhammad of imposing jizya on several bodies jointly and in some cases also imposed the condition that they host Muslims. This rule was followed in most Iranian towns, with the jizya not specified on per capita basis, but being left to the local rulers, though some Muslim commanders stressed the amount on the ability of the ruler to pay. The same wording can be seen in Ibn Amir's treaty. In 652, Ibn Amir sent al-Ahnaf to invade Tokharistan with 4,000 Arabs and 1,000 Iranian Muslims (evidently the Tamimis and asawira), probably because of assistance of its ruler to Yazdegerd's son Peroz. While Marw al-Rudh's garrison agreed to a peace term for the entire district under 300,000 dirhams, the town itself remained besieged. It was the last major stronghold of Sasanians and fell to al-Ahnaf after a fierce battle. After bloody fighting, its marzaban agreed to a peace treaty for 60,000 or 600,000 dirhams as well as a mutual defence pact. He was also allowed to keep his ancestral lands, for the office of marzaban to be hereditary in his family, and to be exempt from taxes along with his whole family. Baladhuri quotes Abu Ubayda as stating that the Turks were supporting the inhabitants of the town. These Turks were Hepthalites, probably from Guzgan, which may explain the reason behind the Arabs next attacking Guzgan, Faryab and Talqan. Al-Mada'ini specifically states that Ahnaf while leading the next expedition, did not want to ask for assistance from the non-Muslims of Marw al-Rudh, probably as he did not trust them. The Arabs camped at Qasr al-Ahnaf, a day's march to the north of Marw al-Rudh. The 30,000-strong army comprising troops of Guzgan, Faryab and Talqan, supported by the Chaghanian troops, advanced to meet them. The battle was inconclusive, but the opposing side dispersed with some remaining at Guzgan while the Arabs withdrew to Marw al-Rudh. Ahnaf sent an expedition, led by al-Aqra' b. Habis and apparently consisting exclusively of Tamimis, to Guzgan. The Arabs defeated Guzgan and entered it by force. Ahnaf meanwhile advanced towards Balkh, making peace treaties with Faryab and Taloqan along the way. The permanent pacification of Khorasan was a protracted affair