CONUBIUM UNDER THE EMPIRE

First of all we must investigate the basic meaning of the term conubium, which was derived from con + nubere (‘marry + to/with’). The usage of conubium as a shorthand for ‘marriage’ occurs occasionally from the late Republic onwards, for example in Livy’s description of the war between Romans and Sabines.

Conubium as a legal right is widely discussed in imperial sources; however, it should be kept in mind that we cannot assume that the same rules applied during the Republic. A starting point is the Rules of Ulpian, written down in the third century CE. Ulpian states:

A rightful marriage exists, when between those who contract a marriage there is conubium [...] Conubium is the ability to take a wife. Roman citizens have conubium with Roman citizens, but with Latins and peregrini only if this has been granted.

Gaius in the second century gives much the same regulations:

Roman citizens are understood to have contracted legal marriage and to have children born from it in their power, if they have married Roman citizen women or Latin or peregrine women with whom they have the right of marriage. For it happens that, because the right of marriage results in children following their father's status, not only do they become Roman citizens, but they are also in their father's power.^[280]

Therefore, the rule was that ‘conubium always means that he who is born follows the condition of the father'.^[281]

Therefore, someone enjoying conubium would be able to contract a iustum matrimonium according to the rights of Roman citizens. Thus, conubium was ‘the right to contract a marriage with a foreigner which will be upheld in a Roman court of law, with full validity of testamentary power and paternity rights'.^[282] Roman citizens could always marry each other, unless there was a legal impediment.^[283] However, being a Roman citizen did not automati­cally carry conubium with everyone else; it was a condition that had to exist between both people.^[284] Marriage with a Latin or peregrine was only possible if conubium had been granted to them, individually or to a whole people or city, by the Roman state.^[285]

Children from such a marriage followed the citizenship status of the highest-ranked partner, at least after the Lex Minicia was introduced (see below). Children from a iustum matrimonium were in patria potestas; without lawful marriage, they were fatherless and sui iuris.^[286] This had important con­sequences for inheritance rights: in case of intestate death, the first heirs were the sui heredes, that is those who were in potestate (legitimate children who had not been emancipated) or manus (wives married in manus, see below);^[287] they now became sui iuris.

In practice, it was difficult to check whether conubium existed between two intended partners; at the census a man had to declare that he had a wife ‘to his best knowledge’ (ex sententia);^[294] since, if he were married without conubium, he would not have a legal wife, the question likely intended to ask whether he was legally married. However, the censors could not easily check the truthfulness of the answer; if the husband and/or wife were Roman citizens, it would have been possible to check previous census lists to see if they had been registered before as such. For a Latin or peregrinus, the only option was to check local census records, but this would have been cumber­some or impossible. Therefore, it may regularly have occurred that a couple discovered they were not legally married, even if they thought they were. The discovery that no conubium existed with a betrothed was a valid reason to end the engagement.^[295] Under the Empire there were regulations about marriage in error, since this may have occurred frequently:

If a Roman citizen man has married a Latin or peregrine wife through ignorance, because he believed that she was a Roman citizen, and has begotten a son, the child is not in his power, because he is not even a Roman citizen, but either a Latin or peregrine [...] By a decree of the Senate it is permitted to prove a case of error, and so the wife also and the son arrive at Roman citizenship, and from that time the son begins to be in his father's power [...] Likewise, if a Roman citizen woman has married a peregrine man through error, as if he were a Roman citizen, it is per­mitted to her to prove a case of error, and so also her son and her husband arrive at Roman citizenship, and equally the son begins to be in his father's power.^[296]

The most important aim was to ensure that children were legitimate, because having legitimate children, and therefore making sure they were legal intestate heirs, was the most important goal of marriage.

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