So ended the last attempt at restoring an independent Sogdiana under the old régime. For some years yet the princes of _S_ughd, Khwārizm, and _T_ukhāristān continued to send appeals to China. The Emperor, however, “preoccupied with maintaining peace, praised them all and gave them consolation, then having warned them sent them back to assure tranquillity in the Western lands.” Abū Muslim had also, it would seem, realised the importance of maintaining relations with the Chinese court, for a succession of embassies from “the Arabs with black garments” is reported, beginning in the year following the battle of the Talas. As many as three are mentioned in a single year. It is possible that these embassies were in part intended to keep the government informed on the progress of the civil wars in China, though the active interest of the new administration in their commerce would, as before, tend to reconcile the influential mercantile communities to ʿAbbāsid rule. The actual deathblow to the tradition of Chinese overlordship in Western Central Asia was given, not by any such isolated incident as the battle of the Talas, but by the participation of Central Asian contingents in the restoration of the Emperor to his capital in 757[113]. Men from the distant lands to whom China had seemed an immeasurably powerful and unconquerable Empire now saw with their own eyes the fatal weaknesses that Chinese diplomacy had so skilfully concealed. From this blow Chinese prestige never recovered.
The complete shattering of the Western Turkish empires by the Chinese policy had also put an end to all possibility of intervention from that side. Transoxania, therefore, was unable to look for outside support, while the reorganization of the Muslim Empire by the early ʿAbbāsid Caliphs prevented, not indeed sporadic though sometimes serious risings, but any repetition of the concerted efforts at national independence. The Shao-wu princes and the more important dihqāns continued to exercise a nominal rule until the advent of the Sāmānids, but many of them found that the new policy of the Empire offered them an opportunity of honourable and lucrative service in its behalf and were quick to take advantage of it. On the other hand the frequent revolts in Eastern Khurāsān under the guise of religious movements show that the mass of the people remained unalterably hostile to their conquerors[114]. In none of these, however, was the whole of Transoxania involved until the rising organized by Rāfiʿ b. Layth three years after the fall of the Barmakids. The extraordinary success of his movement may partly be ascribed to resentment at their disgrace, but it perhaps counted for something that he was the grandson of Na_s_r b. Sayyār. Though the revolt failed it led directly to the only solution by which Transoxania could ever become reconciled to inclusion in the Empire of the ʿAbbāsids. Whether by wise judgment or happy chance, to Maʿmūn belongs the credit of laying the foundations of the brilliant Muhammadan civilisation which the Iranian peoples of Central Asia were to enjoy under the rule of a dynasty of their own race.