After the conquests made by Salm, which probably occupied the years 682 and 683, it seemed as though the Arabs were on the verge of imposing their rule on Transoxania when civil war broke out in the heart of the Empire. Even allowing for the fact that these expeditions were little more than raids, the comparative ease with which the Arabs held to ransom the richest cities in the country is astonishing. The explanation can lie only in their mutual exclusiveness. There is not a hint of united action in the field in _T_abarī’s accounts[32]. A factor which may have exercised some influence was that Sogdiana was completely isolated during these years and unable to look for support from without. The power of the Western Turks was broken by the Chinese armies between 645 and 658; Chinese forces are said to have reached as far west as Kish, and the Emperor Kao-Tsung had officially annexed all the territories formerly included in the Turkish dominions. In the latter year the provinces of Sogdiana and the Jaxartes were organized in sixteen districts, including a “Government of Persia” under the Pērōz already mentioned, situated apparently in Sijistān, possibly even in Eastern Khurāsān[33]. The immediate practical effect of this change of status was of little moment, but her nominal annexation gave China a prestige which was destined to exercise immense influence in determining the attitude of the peoples of Sogdiana to the Arabs. From 670 to 692, however, the new power of Tibet held the Chinese armies in check in the Tarim basin and cut off all possibility of Chinese intervention in the West. The Sogdian princes were thus thrown on their own resources, and, ignorant as yet of the danger behind the Arab raids, they seem to have bowed to the storm. It must not be forgotten that the cities had never before met such an enemy as the Arabs. They had been accustomed to plundering raids by Turks, who disappeared as quickly as they came, and who, disliking to undertake a lengthy siege, were easily appeased by a ransom. Familiar with such nominal annexations, they would naturally adopt the same tactics against the new invaders. Had the Arabs maintained their pressure, there was thus every prospect that Transoxania would have been colonised with a tithe of the expense and loss incurred in its reconquest and would have become as integral a part of the Muslim dominions as Khurāsān. But the opportunity was lost in the fratricidal struggles of the factions, and when the Arabs recommenced their encroachments, the determined resistance offered to their advance showed that the lessons of the first invasion had not been lost on the native princes. _The Withdrawal of the Arabs._