Concubinatus (Latin, "concubinage") was a monogamous union, intended to be long-term but not necessarily permanent, socially and legally recognized as an alternative to marriage in the Roman Empire. It arose in response to Augustan moral legislation that criminalized adultery and imposed penalties on some consensual sexual behaviors outside marriage.

Reasons for choosing concubinatus over marriage varied. If one partner was freeborn and belonged to the senatorial order, and the other was a former slave, they were forbidden by law from marrying. More generally, wealthy widowers or divorced men might avoid the legal complexities of a second marriage in preserving their estates for heirs while still acknowledging a commitment to their partner. However, both partners might be freedpersons,^[2] with the benefits of concubinatus over marriage for people of this status not entirely clear in the historical record. Concubinatus was distinguished in Roman law from contubernium, a de facto marriage in which the partners were both slaves or one was a slave and the other a freedperson.^[3]

The female partner, almost always the person of lower social rank, was a concubina, "concubine" (a "bedmate", one for lying with), a socially respectable role in contrast to the paelex, a sexual partner who was a rival to a wife. The naming of concubinae as such in epitaphs indicates that the role was not inherently disreputable, and juristic texts accord the concubina certain protections. In Latin literature, however, concubinae are more often disparaged as female slaves kept as sexual luxuries, sometimes along with eunuchs.^[4] The discrepancy lies in whether the union was legally verifiable as monogamous concubinatus; an ancilla (female slave as part of a household) might be kept as a concubine and referred to as such but was not eligible for the privileges of formal concubinage.^[5] The equivalent term for a male, concubinus, is used only informally, most often for a same-sex relationship.

Paelex

Although the role and status of "concubine" during the Roman Empire poses some ambiguities of usage, the difference between the Imperial concubina and a paelex or concubine in the Republican era is fairly straightforward: the paelex was a woman "installed" by a married man as a sexual rival to his wife,^[6] whereas the concubina played the role of wife as companion as well as sexual partner.

According to the 2nd-century antiquarian Aulus Gellius, in early Rome paelex was a disparaging word for a woman in a continuing sexual liaison with a man who had also contracted an archaic form of marriage cum manu, meaning that he held patriarchal power over his wife.^[7] In a much-cited law attributed to the semilegendary Numa Pompilius, second king of Rome (ca. 716–673 BCE), a concubine (paelex, not a concubina) was barred from the cultivation of Juno, the goddess of marriage: "a paelex shall not touch the altar of Juno. If she touches it, she shall sacrifice, with her hair unbound, a ewe lamb to Juno."^[8] The paelex in Latin literature is a woman perceived as a sexual threat by the wife, just as Juno was perpetually aggrieved by her husband Jupiter's "affairs", few if any of which were perpetrated with willing partners. In mythology, particularly in the cycle of myths pertaining to the Trojan War, the paelex is often a war captive and hence slave brought into the home as booty by the returning husband. The word paelex is so used by the comic playwright Plautus and was the title of a lost play by Naevius. Writing under Augustus, Ovid often uses the word paelex for abducted or captive women and for non-wives subjected to domestic rape in the myths he depicts in the Metamorphoses and other works.^[9] In these stories, the paelex is often depicted as foreign or barbarian.

As concubinatus became regularized under Imperial law and the status of the concubina elevated as the extralegal equivalent of a wife within imposed monogamy, usage of paelex inversely degraded so that it came to mean nothing more than a woman who had sex with a married man, and in late antiquity seems to have been a synonym for "prostitute"^[10] or "whore".^[11]

In Roman law

In Augustan legislation such as the leges Iuliae and the lex Papia Poppaea, concubinatus was recognized as an enduring monogamous union in lieu of marriage. A person committed to a concubinatus was not allowed to have a spouse at the same time – a man could not have both a legal wife (uxor) and a concubina.^[12] What legally differentiated concubinage from marriage was a lack of affectio maritalis ("marital affection"), which was the desire of having a legal spouse, raise their rank, make them their equal, or the corresponding intent from the other party involved.^[13][14]

Concubinage first gained legal recognition under Augustus, defined as cohabitation without marital status. Concubinatus came to define many unions considered unsuitable according to Roman custom, such a senator's desire to marry a freedwoman or his cohabitation with a former prostitute.^[15] Concubinatus between a woman of senatorial rank and her former slave was not condoned, in part because the Romans disapproved of the woman having the higher status in relationships that were not socially equal.^[16] A quasi-marital relationship involving a Roman citizen and a foreigner was not considered concubinage but a non-Roman marriage based on international law (matrimonium juris gentium),^[17] without legal consequences except those deriving from the ius gentium. If the couple wanted the formal legal protections of concubinatus, the union had to be registered.^[18]

Children

Concubinatus differed mainly from lawful marriage in the legal status of heirs. The couple's children were naturales, with filius naturalis (feminine filia naturalis) the term used for any child born into a family based on a concubinatus or contubernium union and more generally any child whose biological paternity was known, distinguished from a filius legitimus (born from a legally valid marriage) or spurius (of unknown paternity).^[12] In the later empire, children born into concubinage could be legitimated if the couple married legally, and the emperor could grant legitimation as a special privilege.^[19] However, because an ancilla could not be a partner in concubinatus, her child could not be legitimated simply by calling her a concubina. The purpose of this enactment under Constantine I was to discourage men of decurion rank from cohabiting with ancillae and introducing questions of legitimacy into the family's hereditary civic obligations.^[20] Retroactive legitimation of children was an encouragement for a man of rank to marry the freeborn concubina with whom he had been living monogamously, when he had no legitimate heirs from a previous marriage.^[21]

Roman inheritance law was one reason that a man of high rank would live with a woman in concubinage after the death of his first wife; the claims of his children from the first marriage could not be challenged by naturales children from the later union.^[18] Marcus Aurelius had a concubina rather than remarrying so that relations with his children would not be complicated by a stepmother.^[22] Children are mentioned infrequently in connection with concubinatus, and in her study of the subject Beryl Rawson wondered whether children were perhaps not particularly desired from this relationship.^[23]

Concubina

The title of concubine was not necessarily derogatory in ancient Rome, as it was inscribed on tombstones.^[18] Concerning the difference between a concubine and a wife, the jurist Julius Paulus wrote in his Opinions that "a concubine differs from a wife only in the regard in which she is held", meaning that a concubine was not considered a social equal to her patron, as his wife ideally was.^[24] No freeborn women (ingenuae) are identified as concubinae; they are mostly former slaves.^[2]

Later the jurist Ulpian wrote on the Lex Julia et Papia, "Only those women with whom intercourse is not unlawful can be kept in concubinage without the fear of committing a crime."^[25] He also said that "anyone can keep a concubine of any age unless she is less than twelve years old",^[25] twelve being the legal age of betrothal for Roman girls, and fourteen for boys.^[26]

Even an informal concubina who was a slave had some protections under the law. If her owner went bankrupt, nearly all his assets were subject to being seized by creditors and sold, excluding personal possessions such as clothes and slaves who were established in the household as personal attendants. Among these exclusions were a concubina and any natural children he had fathered with a female slave, as Roman law tended to discourage breaking up families.^[27] In late antiquity, an "obscure" constitutio under Justinian seems to suggest that if an ancilla had lived with her master as his concubine for a long time and until his death, and if he had no other wife at the time, she would be released from slavery and any children they had would be regarded as freeborn.^[28]

Concubinus

The masculine form concubinus might be used of the subordinate male partner of either a man or a woman. Since no same-sex unions were recognized as legal forms of marriage under Roman law, a man's concubinus could not be a partner in concubinatus as a legally recognized form of de facto marriage. Literary references generally treat the concubinus of a man as a form of puer delicatus, a well-groomed slave boy who might be so young that from the perspective of 21st-century sexual ethics the relationship would express pedophilia. In the only extant and complete wedding song from Roman antiquity, Catullus warns the groom that he will have to give up his concubinus, who himself is about to leave boyhood for adolescence.^[29] The imperial biographer Suetonius refers to a concubinus of Galba who remained the emperor's companion as he grew older.^[30] Concubinus might also be used disparagingly of a subordinate male kept at the pleasure of a woman of superior status.^[31] No concubinus is identified as such in any known inscription.^[32]