The Art of War by active 6th century B.C. Sunzi

a thousand swift chariots, as many heavy chariots, and a hundred thousand mail-clad soldiers, [The "swift chariots" were lightly built and, according to Chang Yu, used for the attack; the "heavy chariots" were heavier, and designed for purposes of defence. Li Ch’uan, it is true, says that the latter were light, but this seems hardly probable. It is interesting to note the analogies between early Chinese warfare and that of the Homeric Greeks. In each case, the war-chariot was the important factor, forming as it did the nucleus round which was grouped a certain number of foot-soldiers. With regard to the numbers given here, we are informed that each swift chariot was accompanied by 75 footmen, and each heavy chariot by 25 footmen, so that the whole army would be divided up into a thousand battalions, each consisting of two chariots and a hundred men.] with provisions enough to carry them a thousand _li_, [2.78 modern _li_ go to a mile. The length may have varied slightly since Sun Tzŭ’s time.] the expenditure at home and at the front, including entertainment of guests, small items such as glue and paint, and sums spent on chariots and armour, will reach the total of a thousand ounces of silver per day. Such is the cost of raising an army of 100,000 men.