It is perhaps a sense of symmetry that made the later historians of Egypt and China talk of the earlier phases of their national history as being under dynasties comparable to the dynasties of the later empires, and of such early “Emperors” as Menes (in Egypt) or the First Five Emperors (in China). The early dynasties exercised far less centralized powers than the later ones. Such unity as China possessed under the Shang dynasty was a religious rather than an effective political union. The “Son of Heaven” offered sacrifices for all the Chinese. There was a common script, a common civilization, and a common enemy in the Huns of the north-western borders. The last of the Shang Dynasty was a cruel and foolish monarch who burnt himself alive (1125 B.C.) in his palace after a decisive defeat by Wu Wang, the founder of the Chow Dynasty. Wu Wang seems to have been helped by allies from among the south-western tribes as well as by a popular revolt. For a time China remained loosely united under the Chow emperors, as loosely united as was Christendom under the popes in the Middle Ages; the Chow emperors had become the traditional high priests of the land in the place of the Shang Dynasty and claimed a sort of overlordship in Chinese affairs, but gradually the loose ties of usage and sentiment that held the empire together lost their hold upon men’s minds. Hunnish peoples to the north and west took on the Chinese civilization without acquiring a sense of its unity. Feudal princes began to regard themselves as independent. Mr. Liang-Chi-Chao,[118] one of the Chinese representatives at the Paris Conference of 1919, states that between the eighth and fourth centuries B.C. “there were in the Hwang-ho and Yang-tse valleys no less than five or six thousand small states with about a dozen powerful states dominating over them.” The land was subjected to perpetual warfare (“Age of Confusion”). In the sixth century B.C. the great powers in conflict were Ts’i and Ts’in, which were northern Hwang-ho states, and Ch’u, which was a vigorous, aggressive power in the Yang-tse valley. A confederation against Ch’u laid the foundation for a league that kept the peace for a hundred years; the league subdued and incorporated Ch’u and made a general treaty of disarmament. It became the foundation of a new pacific empire. The knowledge of iron entered China at some unknown date, but iron weapons began to be commonly used only about 500 B.C., that is to say two or three hundred years or more after this had become customary in Assyria, Egypt, and Europe. Iron was probably introduced from the north into China by the Huns.