A marital companion of inferior status to a wife.
Royal concubines were standard among the kings of Israel and Judah, just as in any ancient Near Eastern kingdom (Song 6:8-9). They were clearly distinguished from the wives. To lie with a monarch’s concubine was tantamount to usurpation of the throne.
The role of the concubine as the mother of venerable ethnic groups is not overlooked in the genealogies. Their descendants are usually classed as secondary or subsidiary tribes, especially in the Abrahamic groups.
The term concubine is also applied to a handmaiden who had borne children to her mistress’ husband. Such a relationship was usually established because the legal wife was barren (Gen. 16).
In the Talmudic Period and the Middle Ages. There is no evidence of actual concubinage in the Talmud, nor is there any evidence of it in practice during the Middle Ages. In the Middle Ages concubinage was formally forbidden by the rabbis as immoral.
A concubine may be defined by Jewish laws as a woman dedicating herself to a particular man, with whom she cohabits without kiddushin or ketubbah.
There are divided opinions in the codes on the question of whether the taking of a concubine is prohibited or permitted. Some of the posekim are of the opinion that neither pentateuchal nor rabbinical law forbids it, if the woman observes the rules concerning the Mikvah so that the man should not cohabit with her during her period of menstruation. Others are of the opinion that although it is not legally prohibited, one should refrain from taking a concubine, and they caution against her.
Since more recent times it is unanimously accepted that the taking of a concubine is prohibited: “At the present time a woman is permitted to no man except to his husband. In the case of a married man, in the same way as he is prohibited from taking and additional wife both for the protection of his wife and because his taking a concubine -since he is aware that he must not take an additional wife- can only be for the purpose of prostituting, and this is forbidden in the opinion of all the pose Kim (Rashba, Resp., vol. 4, no. 314; Ozar ha-Posekim EH 1, n. 4; 26, n. 5).