Marriage () was a fundamental institution of society in ancient Rome and was used by Romans primarily as a tool for interfamilial alliances. The institution of Roman marriage was a practice of marital monogamy: Roman citizens could have only one spouse at a time in marriage but were allowed to divorce and remarry. This form of prescriptively monogamous marriage that co-existed with male resource polygyny (powerful men can have one wife and many other sexual partners) in Greco-Roman civilization may have arisen from the relative egalitarianism of democratic and republican city-states. Early Christianity embraced this ideal of monogamous marriage by adding its own teaching of sexual monogamy, and propagating it worldwide to become an essential element in many later Western cultures.

Roman marriage had precedents in myth. The abduction of the Sabine women may reflect the archaic custom of bride abduction. Rome's Sabine neighbours rejected overtures of intermarriage by Romulus and his band of male immigrants. According to Livy, Romulus and his men abducted the Sabine maidens but promised them honorable marriage, in which they would enjoy the benefits of property, citizenship, and children.

Marriages helped families to build economic and political bonds and alliances. Matrimonium, the root of the English word matrimony, defined the role of wives as mothers (matres) who would produce legitimate children, as eventual heirs to their parents' estates. The most ancient form of marriage, traditionally reserved to the patrician social class, claimed the husband's right to control his wife and her property. In later developments, the bride retained control over her dowry; the resources of both parties formed a heritable estate.

During the Republican era, marriage, divorce and adultery were matters dealt with by the families concerned. Falling marriage and birth rates in the Later Republic and early Empire led to state intervention. Adultery was made a crime, for which citizen-women could be punished by divorce, fines and demotion in social status; men's sexual activity was adultery only if committed with a married citizen-woman. Families were also offered financial incentives to have as many children as possible. Both interventions had minimal effect.

Conventions of Roman marriage

Marriage () was one of the fundamental institutions of Roman society, as it joined not only two individuals but two families. The Romans considered marriage a partnership, whose primary purpose was to have legitimate descendants to whom property, status, and family qualities could be handed down through the generations.

The institution of marriage in ancient Rome was a strictly marital monogamy: under Roman law, a Roman citizen, whether male or female, could have only one spouse in marriage at a time but were allowed to divorce and remarry. The practice of marital monogamy that co-existed with male resource polygyny distinguished the Greeks and Romans from ancient civilizations in which elite males typically had multiple wives in the institution of marriage. Walter Scheidel believes that Greco-Roman monogamy in marriage may have arisen from the relative egalitarianism of the democratic and republican political systems of the city-states. The aspect of a marital monogamy was later embraced by early Christianity, which in turn perpetuated it with its own teaching of sexual monogamy as an ideal in later Western cultures. In the early fifth century Augustine referred to it as a "Roman custom".

Marriage had mythical precedents, starting with the abduction of the Sabine Women, which may reflect the archaic custom of bride abduction. Romulus and his band of male immigrants approached the Sabines for conubium, the legal right to intermarriage, from the Sabines. According to Livy, Romulus and his men abducted the Sabine maidens, but promised them an honorable marriage, in which they would enjoy the benefits of property, citizenship, and children.Treggiari, Susan (1991). Roman Marriage. New York: Oxford University Press. esp. pp. 8f.

Under Roman law, the oldest living male, the "father of the family" (pater familias), held absolute authority (patria potestas) over his children and, to a lesser extent, his wife. His household was thus understood to be under his manus (literally, "hand").Bruce W. Frier and Thomas A.J. McGinn, A Casebook on Roman Family Law (Oxford University Press, 2004), p. 20. He had the right and duty to seek a good and valuable match for his children and might arrange a child's betrothal long before they came of age.Frier, A Casebook on Roman Family Law, p. 66. To further the interests of their birth families, sons of the elite should follow their fathers into public life,Beryl Rawson, "The Roman Family," in The Family in Ancient Rome: New Perspectives (Cornell University Press, 1986), p. 18. and daughters should marry into respectable families. If a daughter could prove the proposed husband to be of bad character, she could legitimately refuse the match.Rawson, "The Roman Family", p. 21.

The age of lawful consent to a marriage was 12 for girls and 14 for boys.Beryl Rawson, "The Roman Family in Italy" (Oxford University Press, 1999), p. 21. Most Roman women married in their early teens to young men in their twenties.Judith P. Hallett, Fathers and Daughters in Roman Society: Women and the Elite Family (Princeton University Press, 1984), 252; cf. 46, 59, 67. See also Μ. K. Hopkins, "The Age of Roman Girls at Marriage," Population Studies 18 (1965): 309–327.

Roman mores idealized a married daughter's relationship to her father as deferential and obedient, even at her husband's expense.Hallett, 139. "Deference" was not always absolute. After arranging his daughter's first two marriages, Marcus Tullius Cicero disapprovedrightly, as it turned outof her choice to marry Publius Cornelius Dolabella, but found himself unable to prevent it.Rawson, "The Roman Family", p. 21. A daughter kept her own birth-family name (nomen) for life, and although children usually took the father's name, some might take their mother's family name as part of theirs.Rawson, "The Roman Family," p. 18. In the early Empire, the legal standing of daughters differed little, if at all, from that of sons; either could inherit a share of the family estate if their father died intestate.Frier, A Casebook on Roman Family Law, pp. 19–20.

Marriage laws Early Roman law recognized three kinds of marriage: , symbolized by the sharing of spelt bread (panis farreus); coemptio, "by purchase"; and by usus (habitual cohabitation). Patricians always married by confarreatio, while plebeians married by coemptio or usus: in the latter, a woman could avoid her husband's legal control simply by being absent from their shared home for three consecutive nights once a year. Among elite families of the early Republic, manus marriage was the norm;The late Imperial Roman jurist Gaius writes of manus marriage as something that used to happen. Frier and McGinn, Casebook, p. 54. the bride passed from the manus ("hand") of her father to the manus of her husband, remaining under one or another form of male potestas (power).Frier and McGinn, Casebook, p. 53.

Manus marriage was an institutionally unequal relationship. By the time of Julius Caesar, it was largely abandoned in favor of "free" marriage,David Johnston, Roman Law in Context (Cambridge University Press, 1999), pp. 33–34. when a wife moved into her husband's home, she remained under her father's lawful authority, but she did not conduct her daily life under his direct scrutiny,"If adults sons or daughters and their children had lived in the same household as the paterfamilias," notes Rawson, "they may well have found the constant awareness of his powers and position a great strain" ("The Roman Family," p. 15). and her husband had no legal power over her.Frier and McGinn, Casebook, pp. 19–20. This was one of the factors in the independence Roman women enjoyed, relative to many other ancient cultures and up to the modern period:Eva Cantarella, Pandora's Daughters: The Role and Status of Women in Greek and Roman Antiquity (Johns Hopkins University Press, 1987), pp. 140–141. Free marriage usually involved two citizens of equal or near-equal status, or a citizen and a person who held Latin rights. In the later Imperial period and with official permission, soldier-citizens and non-citizens could marry in law. So total was the law's separation of property that gifts between spouses were recognized as conditional loans; if a couple divorced or even lived apart, the giver could reclaim the gift.Frier and McGinn, Casebook, pp. 49, 52, citing Ulpian, D. 24.1.3.1. If the donor died first, the gift to the surviving spouse was valid.

Following the collapse of the Republic, laws about marriage, parenting, and adultery were part of Augustus' program to restore the mos maiorum (traditional social norms) while consolidating his power as princeps and pater familias of the Roman state.Edwards, pp. 34ff., 41–42 et passim; and "Unspeakable Professions: Public Performance and Prostitution in Ancient Rome," in Roman Sexualities (Princeton University Press, 1997), pp. 67, 89–90 et passim. Marriage and remarriage had become less frequent, and the citizen birth rate had fallen, particularly among the wealthier, more leisured classes. Augustan law on marriage and family life encouraged marriage, having children, and punished adultery as a crime.Lefkowitz, p. 102. The new legislation formalized and enforced what had been considered a traditional, moral duty to family and the State; all men between 25 and 60 years of age, and all women between 20 and 50 were to marry and have children, or pay extra tax in proportion to their wealth. Members of the upper classes thus had most to lose. Citizens who had already produced three children, and freed persons who had produced four, were exempt. Marriages between senators, freed women, enslaved people and citizens were declared legally void. Children born to such liaisons were illegitimate, non-citizen and unable to inherit.Frank, Richard I., "Augustus' Legislation on Marriage and Children," California Studies in Classical Antiquity, Vol. 8, 1975, pp. 44–45 University of California Press A married woman who bore three children or more could be granted legal independence under the ius liberorum.Thomas, "The Division of the Sexes," p. 133. These laws were poorly received; they were modified in 9 AD by the Lex Papia Poppaea; eventually, they were nearly all repealed or fell into disuse under Constantine and later emperors, including Justinian.

Roman citizen women could have only one sexual partner at a time but allowed divorce and remarriage. In the case of Roman citizen men, it is not clear whether the condition that a man is not able to have a concubine at the time that he has a wife pre-dates or post-dates the Constantinian law; ie., whether concubinage existed concurrently with marriage for men in Ancient Rome has been debated in modern scholarship and the evidence is inconclusive: it was not until the sixth century CE, after centuries of Christian influence, that the emperor Justinian claimed that “ancient law” prohibited husbands from keeping wives and concubines at the same time. According to Walter Scheidel, conditions in the Ancient Rome are best defined as prescriptively monogamous marriage that co-existed with male resource polygyny; powerful men had a principal wife and several secondary sexual partners. A married man's sexual activities with slaves, prostitutes, or other women of low status were not, in legal terms, adultery, and he could not be prosecuted under Augustus Laws. Under the adultery law, married man would only be committing adultery if his lover were someone else's wife.

Wedding ceremonies