An Lu-shan's rebellion marks a turning point in practically every aspect of the history of the T'ang dynasty. The strong centralized empire which reached the apogee of its magnificence under the Emperor Hsiian Tsüng (713–56) was able, after seven years of exertion, to put down the rebellion. But in doing so it was forced to compromise with the very principle of provincial military autonomy of which An Lu-shan was the arch-representative. The empire which remained in the hands of the T'ang imperial family deteriorated by degrees into a state of provincial autonomy which differed from the actual subdivision of China during the ensuing Five Dynasties period more in name than in reality.