After the downfall of the Han dynasty, a long period of civil war ensued, in which the destruction of life and property was so enormous that the population was reduced to one-sixth of the amount set down in A.D. 230, when disease, epidemics, and earthquakes increased the losses caused by war and the cessation of agriculture, according to Ma Twan-lin; and it is not till A.D. 280, when the Tsin dynasty had subjected all to its sway, that the country began to revive. In that year an enumeration was made which stated the free people between 12 and 66 years in the land at 14,163,863, or 23,180,000 in all. From this period till the Sui dynasty came into power, in 589, China was torn by dissensions and rival monarchs, and the recorded censuses covered only a portion of the land, the figures including even fewer of the people, owing to the great number of serfs or bondmen who had sought safety under the protection of landowners. At this time a new mode of taking the census was ordered, in which the people were classified into those from 1 to 3 years, then 3 to 10, then 10 to 17, and 17 to 60, after which age they were not taxed; the ratio of the land tax was also fixed. A census taken in 606 in this way gives an estimated population of 46,019,956 in all China; the frontiers, at this period, hardly reached to the Nan ling Mountains, and the author’s explanation of the manner of carrying on some public works shows that even this sum did not include persons who were liable to be called on for personal service, while all officials, slaves, and beggars were omitted. Troubles arose again from these enforced works, and it was not till the advent to power of the Tang dynasty, in 618, that a regular enumeration was possible. This family reigned 287 years, and Ma Twan-lin gives fifteen returns of the population up to 841. They show great variations, some of them difficult to explain even by omitting or supplying large classes of the inhabitants. The one most carefully taken was in A.D. 754, and gives an estimated total of about seventy millions for the whole Empire, which, though nearly the same as that in the Han dynasty in A.D. 2, extended over a far greater area, even to the whole southern seaboard. In addition to former enumerated classes, many thousands of priests were passed by in this census.