Matriarchy is a social system in which females (most notably in mammals) hold the primary power positions in roles of political leadership, moral authority, social privilege and control of property at the specific exclusion of males — at least to a large degree.
While those definitions apply in general English, definitions specific to the disciplines of anthropology and feminism differ in some respects. Most anthropologists hold that there are no known anthropological societies that are unambiguously matriarchal, but some authors believe exceptions may exist or may have.
Matriarchies may also be confused with matrilineal, matrilocal, and matrifocal societies. A few people consider any non-patriarchal system to be matriarchal, thus including genderally equalitarian systems (Peggy Reeves Sanday favors redefining and reintroducing the word matriarchy, especially in reference to contemporary matrilineal societies such as the Minangkabau), but most academics exclude them from matriarchies strictly defined.
In 19th-century Western scholarship, the hypothesis of matriarchy representing an early, mainly prehistoric, stage of human development gained popularity. Possibilities of so-called primitive societies were cited and the hypothesis survived into the 20th century, including in the context of second-wave feminism. This hypothesis was criticized by some authors such as Cynthia Eller in The Myth of Matriarchal Prehistory and remains as a largely unsolved question to this day. Some older myths describe matriarchies.
Several modern feminists have advocated for matriarchy now or in the future and it has appeared in feminist literature. In several theologies, matriarchy has been portrayed as negative.