It was a rule of the civil law that if a man in good faith bought a thing, or received it by way of gift, or on any other lawful ground, from a person who was not its owner, but whom he believed to be such, he should acquire it by usucapion—if a movable, by one year's possession, and by two years' possession if an immovable, though in this case only if it were in Italian soil;—the reason of the rule being the inexpediency of allowing ownership to be long unascertained. The ancients thus considered that the periods mentioned were sufficient to enable owners to look after their property; but we have arrived at a better opinion, in order to save people from being overquickly defrauded of their own, and to prevent the benefit of this institution from being confined to only a certain part of the empire. We have consequently published a constitution on the subject, enacting that the period of usucapion for movables shall be three years, and that ownership of immovables shall be acquired by long possession—possession, that is to say, for ten years, if both parties dwell in the same province, and for twenty years if in different provinces; and things may in these modes be acquired in full ownership, provided the possession commences on a lawful ground, not only in Italy but in every land subject to our sway.

1 Some things, however, not withstanding the good faith of the possessor, and the duration of his possession, cannot be acquired by usucapion; as is the case, for instance, if one possesses a free man, a thing sacred or religious, or a runaway slave.

2 Things again of which the owner lost possession by theft, or possession of which was gained by violence, cannot be acquired by usucapion, even by a person who has possessed them in good faith for the specified period: for stolen things are declared incapable of usucapion by the statute of the Twelve Tables and by the lex Atinia, and things taken with violence by the lex Iulia et Plautia.

3 The statement that things stolen or violently possessed cannot, by statute, be acquired by usucapion, means, not that the thief or violent dispossessor is incapable of usucapion—for these are barred by another reason, namely the fact that their possession is not in good faith; but that even a person who has purchased the thing from them in good faith, or received it on some other lawful ground, is incapable of acquiring by usucapion. Consequently, in things movable even a person who possesses in good faith can seldom acquire ownership by usucapion, for he who sells, or on some other ground delivers possession of a thing belonging to another, commits a theft.

4 However, this admits of exception; for if an heir, who believes a thing lent or let to, or deposited with, the person whom he succeeds, to be a portion of the inheritance, sells or gives it by way of dowry to another who receives it in good faith, there is no doubt that the latter can acquire the ownership of it by usucapion; for the thing is here not tainted with the flaw attaching to stolen property, because an heir does not commit a theft who in good faith conveys a thing away believing it to be his own.

5 Again, the usufructuary of a female slave, who believes her offspring to be his property, and sells or gives it away, does not commit a theft: for theft implies unlawful intention.

6 There are also other ways in which one man can transfer to another property which is not his own, without committing a theft, and thereby enable the receiver to acquire by usucapion.

7 Usucapion of property classed among things immovable is an easier matter; for it may easily happen that a man may, without violence, obtain possession of land which, owing to the absence or negligence of its owner, or to his having died and left no successor, is presently possessed by no one. Now this man himself does not possess in good faith, because he knows the land on which he has seized is not his own: but if he delivers it to another who receives it in good faith, the latter can acquire it by long possession, because it has neither been stolen nor violently possessed; for the idea held by some of the ancients, that a piece of land or a place can be stolen, has now been exploded, and imperial constitutions have been enacted in the interests of persons possessing immovables, to the effect that no one ought to be deprived of a thing of which he has had long and unquestioned possession.

8 Sometimes indeed even things which have been stolen or violently possessed can be acquired by usucapion, as for instance after they have again come under the power of their real owner: for by this they are relieved from the taint which had attached to them, and so become capable of usucapion.

9 Things belonging to our treasury cannot be acquired by usucapion. But there is on record an opinion of Papinian, supported by the rescripts of the Emperors Pius, Severus, and Antoninus, that if, before the property of a deceased person who has left no heir is reported to the exchequer, some one has bought or received some part thereof, he can acquire it by usucapion.

10 Finally, it is to be observed that things are incapable of being acquired through usucapion by a purchaser in good faith, or by one who possesses on some other lawful ground, unless they are free from all flaws which vitiate the usucapion.

11 If there be a mistake as to the ground on which possession is acquired, and which it is wrongly supposed will support usucapion, usucapion cannot take place. Thus a man's possession may be founded on a supposed sale or gift, whereas in point of fact there has been no sale or gift at all.

12 Long possession which has begun to run in favour of a deceased person continues to run on in favour of his heir or praetorian successor, even though he knows that the land belongs to another person. But if the deceased's possession had not a lawful inception, it is not available to the heir or praetorian successor, although ignorant of this. Our constitution has enacted that in usucapion too a similar rule shall be observed, and that the benefit of the possession shall continue in favour of the successor.

13 The Emperors Severus and Antoninus have decided by a rescript that a purchaser too may reckon as his own the time during which his vendor has possessed the thing.

14 Finally, it is provided by an edict of the Emperor Marcus that after an interval of five years a purchaser from the treasury of property belonging to a third person may repel the owner, if sued by him, by an exception. But a constitution issued by Zeno of sacred memory has protected persons who acquire things from the treasury by purchase, gift, or other title, affording them complete security from the moment of transfer, and guaranteeing their success in any action relating thereto, whether they be plaintiffs or defendants; while it allows those who claim any action in respect of such property as owners or pledges to sue the imperial treasury at any time within four years from the transaction. A divine constitution which we ourselves have lately issued has extended the operation of Zeno's enactment, respecting conveyances by the treasury, to persons who have acquired anything from our palace or that of the Empress.