About the origin of Japanese slavery, much remains to be learned. There are evidences of successive immigrations; and it is possible that some, at least, of the earlier Japanese settlers were reduced by later invaders to the status of servitude. Again, [234] there was a considerable immigration of Koreans and Chinese, some of whom might have voluntarily sought servitude as a refuge from worse evils. But the subject remains obscure. We know, however, that degradation to slavery was a common punishment in early times; also, that debtors unable to pay became the slaves of their creditors; also, that thieves were sentenced to become the slaves of those whom they had robbed.* Evidently there were great differences in the conditions of servitude. The more unfortunate class of slaves were scarcely better off than domestic animals; but there were serfs who could not be bought or sold, nor employed at other than special work; these were of kin to their lords, and may have entered voluntarily into servitude for the sake of sustenance and protection. Their relation to their masters reminds us of that of the Roman client to the Roman patron. [*An edict issued by the Empress Jito, in 690, enacted that a father could sell his son into real slavery; but that debtors could be sold only into a kind of serfdom. The edict ran thus: "If a younger brother of the common people is sold by his elder brother, he should be classed with freemen; if a child is sold by his parents, he should be classed with slaves; persons confiscated into slavery, by way of payment of interest on debts, are to be classed with freemen; and their children, though born of a union with a slave, are to be all classed with freemen."--Aston's Nihongi, Vol. II, p, 402.] As yet it is difficult to establish any clear distinction between the freedmen and the freemen of ancient Japanese society; but we know that the free population, ranking below the ruling class, [235] consisted of two great divisions: the kunitsuko and the tomonotsuko. The first were farmers, descendants perhaps of the earliest Mongol invaders, and were permitted to hold their own lands independently of the central government: they were lords of their own soil, but not nobles. The tomonotsuko were artizans,--probably of Korean or Chinese descent, for the most part,--and numbered no less than 180 clans. They followed hereditary occupations; and their clans were attached to the imperial clans, for which they were required to furnish skilled labour. Originally each of the O-uji and Ko-uji had its own territory, chiefs, dependants, serfs, and slaves. The chieftainships were hereditary,--descending from father to son in direct succession from the original patriarch. The chief of a great clan was lord over the chiefs of the subclans attached to it: his authority was both religious and military. It must not be forgotten that religion and government were considered identical.