The Rashīdī History 9.2.8

9.2.8

During the first half of the fifteenth century, both these towns, though situated close to Turfan, were reckoned independent, and sent their own tribute, separately, to Peking; and it was only when Turfan became powerful, after the middle of the century, that they were annexed to their more important neighbour. This would have been only very shortly before the commencement of the reign of Sultan Ahmad, or when we come to corresponding names and dates in the two lists. At this time, it may be, the custom was changed, and the reigning Khan may have begun to send the tribute missions in his own name; while the names—especially the non-Musulman ones—of the subordinate chiefs, would have tended soon to fall into oblivion and remain unnoticed by Muhammadan writers. This, however, is only a suggestion—a possible explanation of the discrepancies.