CONCUBINATUS
concubinatus (kon-kyoo-bi-nay-t<<schwa>>s), n. [Latin “concubinage”] Roman law. A permanent, mono-gamous union of a man and a woman who are not legally married. • Concubinatus was not prohibited by law, but carried fewer benefits than a legal marriage. Cf. JUSTAE NUPTIAE.
“[C]oncubinage (concubinatus) … was something to which we have no precise analogue in modern law, for, so far from being prohibited by the law, it was regulated thereby, being treated as a lawful connexion. It is almost a sort of unequal marriage (and is practically so described by some of the jurists) existing between persons of different station — the man of superior rank, the woman of a rank so much inferior that it is not to be presumed that his union with her was intended to be a marriage.” James Bryce, “Marriage and Divorce under Roman and English Law,” in 3 Select Essays in Anglo-American Legal History 806–07 (1909). [Blacks Law 8th]