As the struggle for pre-eminency which we are about to describe involved bloodthirsty combats extending almost uninterruptedly over five centuries, it may be of interest to inquire of what consisted the paraphernalia of warfare in those days. It appears that among the Chinese federal princes, who, as we have seen, only occupied in the main the flat country on the right bank of the Yellow River, war-chariots were invariably used, which is the more remarkable in that after the Conquest in 220 B.C. of China by the First August Emperor of Ts'in, and down to this day, war-chariots have scarcely ever once been even named, at least as having been marshalled in serious battle array. The Emperor alone was supposed in true feudal times to possess a force of 10,000 chariots, and even now a "10,000-chariot" state is the diplomatic expression for "a great power," "a power of the first rank," or "an empire." No vassal was entitled to more than 1000 war-chariots. In the year 632 B.C., when Tsin inflicted a great defeat upon its chief rival Ts'u, the former power had 700 chariots in the field. In 589 B.C. the same country, with 800 chariots included in its forces, marched across the Yellow River and defeated the state of Ts'i, its rival to the east. Again in 632 Tsin offered to the Emperor 100 chariots just captured from Ts'u, and in 613 sent 800 chariots to the assistance of a dethroned Emperor. The best were made of leather, and we may assume from this that the wooden ones found it very difficult to get safely over rough ground, for in a celebrated treaty of peace of 589 B.C. between the two rival states Tsin and Ts'i, the victor, lying to the west, imposed a condition that "your ploughed furrows shall in future run east and west instead of north and south," meaning that "no systematic obstacles shall in future be placed in the way of our invading chariots."