Abalienation, in Roman law, signifies a sort of alienation [1] by which the effects known as res manicipi [2] were transferred to persons entitled to acquire them, either by a formula known as traditio nexu, [3] or by a renunciation that was performed before a court. See Alienation.

This word is composed of ab, and alienare, to alienate. The effects that are here called res mancipi, and that were the object of abalienation , were chattel, slaves, lands, and other possessions within the borders of Italy. Persons entitled to acquire them were Roman citizens, the Latins, and some foreigners to whom this commerce was exceptionally allowed. The transaction took place either with the ceremony of weights and with money in hand, or else by a withdrawal in the presence of a magistrate.

1. That is, the transfer of property or ownership rights to another party. Mancipium or mancipatio was the legal possession, or transfer of a thing via certain legal forms ( mancipatio ), such as the presence of five witnesses of proper age and status, which in Roman law were required for the ownership of a certain category of property ( res mancipi ) that included land, animals, slaves, or, for that matter, children of Roman parents. See William Smith, A Dictionary of Greek and Roman Antiquities (London: John Murray, 1875), “Mancipium.” In early Roman law only “quiritarian ownership” was recognized as valid, and, as explained in the article, transfer of this could only take place between Roman citizens or those who held the commercium, as he right to hold such ownership was called when it was vested in a non-citizen. The term dominium, which refers to paramount ownership, or eminent domain, appears later among legal writers like the jurist Gaius (fl. 130-180 CE).

2. A category of property in Roman law that was especially important in the history of early Rome. Res mancipi differed from res nec mancipi in that res mancipi can only be conveyed via a formal ceremony or legal proceeding involving a magistrate.

3. Smith, in the same article, comments: “ [M]ancipatio or the older term mancipium is equivalent to ‘ traditio nexu’ : in other words mancipium was a nexus or nexum . Cicero ( De Harusp. respons. c7) uses both words in the same sentence, where he speaks of various title to property, and among them he mentions the Jus mancipii and Jus nexi . He may mean here to speak of the Jus mancipii in its special sense as contrasted with the Jus nexi which had a wider meaning; in another instance he uses both words to express one thing ( Ad Fam. IV.30 ).”