The Origin of the Family, Private Property and the State (1884), was a provocative and profoundly influential critique of the Victorian nuclear family.
Engels argued that the traditional monogamous household was in fact a recent construct, closely bound up with capitalist societies.
Under this patriarchal system, women were servants and, effectively, prostitutes.
Only Communism would herald the dawn of communal living and a new sexual freedom and, in turn, the role of the state would become superfluous.