The Roman family constituted the basic structural framework of Roman society.

The Latin familia means, essentially, “household” and can refer to both persons and things (see Ulpian, D. 50.16.195.1). The concept included all persons under the power of a single head (the paterfamilias) and, in a broader sense, all relatives connected by blood or marriage.

The family was the Roman legal unit par excellence, and its head, the father, the only person with full recognition under Roman law. The power of the head of the family over his descendants lasted not until his children married and developed their own households, but until the father himself died. In the typical case, the Roman family consisted of a legitimately married adult male Roman citizen along with his wife, children, grandchildren, and slaves. The Roman family was traced exclusively through the father’s lineage (patrilineal) and was founded on his absolute control over the other family members: his wife (manus), children (patria potestas), and slaves (mancipium). According to the Romans, the condition of women was below that of men (Papinian, D. 1.5.9). Women were considered weaker than men (Twelve Tables V.1), so the law created more extensive protections for women in legal and business matters. In early stages of Roman family law, moreover, there was little difference between sons and slaves.

The family began with marriage, and marriage was basically a matter of intention: the intention to live together as husband and wife. Beyond that condition, the partners had to have the legal capacity to marry and fall out­side of certain statutory prohibitions. People unable to achieve marital status together could live together in other kinds of sexual partnership.

The Romans established a genuine slave society, i.e., a political community one part of which prevailed and lorded over the other. Freedom was more of a privilege for some citizens than a general right for everyone. According to the Romans, slavery was a social institution of the law of nations that generated great social and economic value. It was regarded as a social need, a pre­rogative of the wealthy, and an appropriate penalty for enemies captured in war. Slaves performed domestic services and worked on farms, in mines, and at mills. They were teachers, physicians, accountants, but also barbers, gla­diators, and mule drivers. By the late first century bce, about 20 to 30 percent of the population in Roman Italy consisted of slaves: more than a million slaves out of a population of about five to six million.