Soon, however, this policy was reversed—possibly due to pressure from the Caliph himself—and the often brutal measures the Arab tax-gatherers employed to gather the taxes from the mawali and the local landed aristocracy (dihqans) led to a general revolt in Transoxiana. This was made all the more dangerous to the Arabs due to the rebels' call for assistance to the Türgesh ruler, the khagan, who replied by leading his army in person against the Arabs. By the time the khagan entered the field in 728, only Samarkand and the two fortresses of Kamarja and Dabusiyya on the Zarafshan River remained in Arab hands in all of Transoxiana.[10][11]