The history of China may be for our present purposes accordingly summed up as follows. The pure Chinese race from time immemorial had been confined to the flat lands of the Yellow River, and its one tributary on the south, the River Loh, the Tartars possessing most of the left bank from the Desert to the sea. However, from the beginning of really historical times the Chinese had been in unmistakable part-possession of the valleys of the Yellow River's two great tributaries towards the west and north, the Wei (in Shen Si) and the Fen (in Shan Si). Little, if any, Chinese colonizing was done much before the Ts'in conquests in any other parts of Tartarland; none in Sz Ch'wan that we know of; little, if any, along the coasts, except perhaps from Ts'i and Lu (in Shan Tung), both of which states seem to have always been open to the sea, though many barbarian coast tribes still required gathering into the Chinese fold. The advance of Chinese civilization had been first down the Yellow River; then down the River Han towards the Middle Yang-tsz; and lastly, down the canals and the Hwai network of streams to the Shanghai coast. Old colonies of Chinese had, many centuries before the conquest of China by the Chou dynasty, evidently set out to subdue or to conciliate the southern tribes: these adventurous leaders had naturally taken Chinese ideas with them, but had usually found it easier for their own safety and success to adopt barbarian customs in whole or in part. These mixed or semi-Chinese states of the navigable Yang-tsz Valley, from the Ich'ang gorges to the sea, had generally developed in isolation and obscurity, and only appeared in force as formidable competitors with orthodox Chinese when the imperial power began to collapse after 771 B.C. The isolation of half-Roman Britain for several centuries after the first Roman conquest, and the departure of the last Roman legions, may be fitly compared with the position of the half-Chinese states. Ts'u, Wu, and Yueeh all had pedigrees, more or less genuine, vying in antiquity with the pedigree of the imperial Chou family; and therefore they did not see why they also should not aspire to the overlordship when it appeared to be going a-begging. Even orthodox Tsin and Ts'i in the north and north-east were in a sense colonial extensions, inasmuch as they were governed by new families appointed thereto by the Chou dynasty in 1122 B.C., in place of the old races of rulers, presumably more or less barbarian, who had previously to 1122 B.C. been vassal - in name at least - to the earlier imperial Hia and Shang dynasties: but these two great states were never considered barbarian under Chou sway; and, indeed, some of the most ancient mythological Chinese emperors anterior to the Hia dynasty had their capitals in Tsin and Lu, on the River Fen and the River Sz.