This paper demonstrates how nyau (a male secret society) rede fined relations in Chewa matrilineages in accordance with developments that the Chewa witnessed from the mid-nineteenth century. Thanks to nyau and the relatively hands-off approach the colonial state adopted towards its activities, the Chewa matrilineal system survived the effects of the slave trade, Ngoni and Yao invasions, the spread of Christian missionary teachings, the imposition of colonial rule and the development of capitalism. Nyau accomplished this by ensuring that relations between Chewa men and women remained ambivalent and negotiable. Allowing men to ritually gain increased importance in nyau and indeed in Chewa communities at large not only gave power to men but also ensured their continued involvement in the matrilineages. So, while female prestige declined, as evidenced by the debasement of women by nyau, some important aspects of the matrilineal system, such as matrilocal marriage, were preserved.