To pass their property on to their biological offspring, fathers demanded paternity be established beyond doubt, so necessitating the elimination of female promiscuity. ‘The overthrow of mother right was the world historical defeat of the female sex. The man took command in the home also; the woman was degraded and reduced to servitude; she became the slave of his lust and a mere instrument for the production of children,’ Engels explained. ‘In order to make certain of the wife’s fidelity and therefore of the paternity of the children, she is delivered over unconditionally to the power of the husband; if he kills her, he is only exercising his rights.’ The man, meanwhile, successfully and hypocritically retained his own rights to conjugal infidelity.

— The Origin Of The Family, Private Property, and The State by Friedrich Engels (Page 67)