Serfs though free were in some respects not far removed from slaves. They were found usually in country districts in the provinces, and were often included under the general term "cultivators" (coloni), which was also applied in republican and early imperial times to small farmers, who were freemen not only in law but in practice. The origin and history of this serfdom is not clear. It may very possibly have been developed on the example of Marcus Aurelius' settlement in Italy of numbers of the peoples conquered in the Marcomannic War, and possibly on the example of the German "Liten" (laeti), settled on the Gallic border. But besides conquered tribes retained in their own country or settled in other countries, voluntary contract under pressure of poverty and statutes against beggary probably added to the number. The maintenance of the land tax introduced by Diocletian made the retention of the cultivators on the several estates a necessity.
The characteristic of a serf was that he and his descendants were inseparably attached to the land, and as a rule to one particular farm, specified in the government census, and held under a lord. If this particular part of the lord's estate was over-supplied with cultivators, he might transfer serfs permanently to another part which was undersupplied, in accordance with the purpose of the institution — that of keeping the land under due cultivation and enabling it to bear taxes. But except in such a case the serfs could not be separated from the farm nor the farm from them. They were part of its permanent stock. If the lord sold a part of the land, he must convey with it a proportionate number of the serfs belonging. If a serf wandered or was stolen, or became a cleric without his lord's consent, he could, whatever was the social position to which he had attained, be reclaimed by his lord just as if he were a runaway slave. And for some offences, e.g. marrying a freewoman, he was liable by statute, like a slave, to chains or stripes. He was not admissible to the army, but as a free man he paid poll tax. He could sell the surplus produce of his farm, and his savings, called his peculium, were in a sort his property but were inalienable except in the way of trade; on his death (e.g. as a monk), childless and intestate, they passed to his lord, but usually would pass to his children or other successors on his farm. He might (apparently) own land, and would be entered in the Register as its holder and be liable for the land tax, whereas the tax on the farm to which he was attached as a serf would usually be collected from the lord. A serf was bound to pay a rent to his lord but the rent was certain, usually a fixed portion of the produce but sometimes a sum of money. Against any attempt of the lord to increase the rent, he could bring the case into court, but on all other grounds he was disabled from suing his lord. The rent was called canon or pensio.
The union of serfs was held to be a marriage and accordingly the children were serfs, and even the children of a serf by a freewoman or a slave followed the condition of the father, until Justinian, pressed by the
