CASE 11: Incestuous Marriage
Tituli ex Corpore Ulpiani 5.6-7
(6) Inter parentes et liberos infinite cuiuscumque gradus sint conubium non est.
inter cognatos autem ex transverso gradu olim quidem usque ad quartum gradum matrimonia contrahi non poterant: nunc autem etiam ex tertio gradu licet uxorem ducere, sed tantum fratris filiam, non etiam sororis filiam aut amitam vel materteram, quamvis eodem gradu sint. eam, quae noverca vel privigna vel nurus vel socrus nostra fuit, uxorem ducere non possumus. (7) Si quis eam quam non licet uxorem duxerit, incestum matrimonium contrahit: ideoque liberi in potestate eius non fiunt, sed quasi vulgo concepti spurii sunt.(Excerpts from Ulpian’s Writings)
(6) There is no conubium between ascendants and descendants no matter how far removed. Between collateral relatives, at one time marriages could not be contracted up to the fourth degree. But now it is permitted to take a wife also from the third degree—but only a brother’s daughter, not a sister’s daughter or a paternal or maternal aunt, although they are of the same degree. We cannot take as wife a woman who was our stepmother or stepdaughter or daughter-in-law or mother-in-law.
(7) If someone takes a wife who is not permitted, he contracts an incestuous marriage; so the children (of this marriage) are not in his power but are bastards, as if promiscuously conceived.
1. Degrees of Kinship. All this is explained in great detail by Justinian (Inst.
3.6). Your parents and children are related to you in the first degree (primus gradus); your siblings, grandparents, and grandchildren, in the second degree (secundus gradus); and so on.
You can figure this out by looking at a family tree; if you count persons back from yourself to the closest ancestor that a relative shares with you, and then forward to the relative, you establish the degree of that person's kinship. The Roman rules barring incestuous marriage are established, in principle, on the basis of actual blood relationship, not on the basis of agnation or the usual family structure; thus, for instance, a male ex-slave cannot marry his biological sister (Pomponius, D. 23.2.8: “this rule is derived from morality, not statutes”).2. Endogamy and Exogamy. In most societies, marriage is typically thought of as exogamous, meaning that, at least in principle, the bride and groom come from different social groups and their marriage establishes a link between the groups (group A is linked to group B). In many historical Mediterranean societies, by contrast, marriage seems often to be regarded as endogamous: the primary aim of marriage is to cement a bond within a recognized social group (group A is linked to group A). Where this phenomenon occurs, the boundaries for incestuous marriage tend to be drawn fairly narrowly, and there is frequently an inward pressure on them (i.e., a tendency for relaxed restrictions). At Rome, marriage between ascendants and descendants (e.g., a father or grandfather and a daughter) was probably always forbidden, as this Case indicates. As for collateral relatives, some evidence suggests that the boundary was originally the sixth degree (so that second cousins could not marry), but by the classical period it was drawn at the fourth degree (so that first cousins could marry; for an example, see Case 98) and, as this Case indicates, sometimes even closer. (The exception in this Case was introduced when Emperor Claudius married Agrippina, his fraternal niece; see Gaius, Inst. 1.62. According to the historian Dio Cassius, 68.2.4, it was later repealed.) In your opinion, is the Roman tolerance for close-kin marriage too extreme? Although the evidence is not very good, close-kin marriages were apparently uncommon among at least the Roman upper classes.
In Egypt of the early Roman Empire, by contrast, even full brother-sister marriages were frequent; these marriages were illegal in Roman law.3. Non-Blood Relations. The incest rules tend to be applied more laxly to non-blood relations. Thus, for instance, where there is no blood relationship, a man can marry his adopted sister's daughter (Ulpian, D. 23.2.12.4), but not his adopted sister unless either the bride or the groom is no longer under the fathers power (Gaius, D. 23.2.17 pr.-1). A relation by a terminated marriage is forbidden only in the direct line; so a man cannot marry his stepmother after the end of her marriage with his father (Gaius, Inst. 1.63). However, Gaius (D. 23.2.17.2) states that marriage between a man and his fathers sister is forbidden even when the two are related only as a result of adoption. Should adopted relatives be treated as natural for purposes of incest law?
4. Ignoring the Rules. Does the penalty described in this Case seem to you too harsh? Essentially, the marriage is null and any children are treated as illegitimate, which means that they have no claim on their natural father's estate; further, criminal penalties were applied at least in the later Empire (e.g., Paul, Sent. 2.26.15: deportation to an island). Still, jurists and even emperors often show some leniency, especially to women who enter such marriages through ignorance of the law, particularly where the law is not obvious. A spectacular example is given by the jurist Marcian (D. 23.2.57a), who cites a rescript of Marcus Aurelius writing to a woman: “I am swayed both by the length of time that, through ignorance of the law, you have lived in marriage with your maternal uncle, and by the fact that your grandmother arranged the marriage, and by your many children.
Taking these things together, I confirm the status of your children issuing from this marriage contracted forty years ago, just as if they had been legitimately conceived.” This signal instance of imperial clemency also clearly indicates the sort of circumstances in which such a marriage might arise.5. Bigamy. In A.D. 258, the emperors Valerian and Gallienus wrote (C. 9.9.18): “Official disgrace (infamia) undoubtedly attends a man who has two wives. In this matter we consider, not (just) the enforcement of the law forbidding our citizens to contract multiple marriages, but their mental intent. (1) Nevertheless, in the case of the man who sought to marry you by pretending to be unmarried when he had another wife in a province, a lawful accuser may also charge him with criminal debauchery (stuprum), from which you are insulated because you thought yourself to be a wife.” Note that bigamy is not a crime in itself, although it does lead to praetorian disgrace (infamia, D. 3.2.1); but it is criminal to have sexual relations with the second wife when she is unaware of the bigamy. Why does it make sense under Roman law not to criminalize bigamy? Is the second marriage necessarily invalid? See Case 76. As the rescript indicates, the second wife, had she known of her husbands bigamy, would also be guilty of stuprum.