<P> As polygamy in Africa is increasingly subject to legal limitations, a variant form of de facto (as opposed to legal or de jure) polygyny is being practised in urban centres . Although it does not involve multiple (now illegal) formal marriages, the domestic and personal arrangements follow old polygynous patterns . The de facto form of polygyny is found in other parts of the world as well (including some Mormon sects and Muslim families in the United States). In some societies such as the Lovedu of South Africa, or the Nuer of the Sudan, aristocratic women may become female' husbands .' In the Lovedu case, this female husband may take a number of polygamous wives . This is not a lesbian relationship, but a means of legitimately expanding a royal lineage by attaching these wives' children to it . The relationships are considered polygynous, not polyandrous, because the female husband is in fact assuming masculine gendered political roles . </P> <P> Religious groups have differing views on the legitimacy of polygyny . It is allowed in Islam and Confucianism . Judaism and Christianity have mentioned practices involving polygyny in the past, however, outright religious acceptance of such practices was not addressed until its rejection in later passages . They do explicitly prohibit polygyny today . </P> <P> Polyandry is notably more rare than polygyny, though less rare than the figure commonly cited in the Ethnographic Atlas (1980) which listed only those polyandrous societies found in the Himalayan Mountains . More recent studies have found 53 societies outside the 28 found in the Himalayans which practice polyandry . It is most common in egalitarian societies marked by high male mortality or male absenteeism . It is associated with partible paternity, the cultural belief that a child can have more than one father . </P> <P> The explanation for polyandry in the Himalayan Mountains is related to the scarcity of land; the marriage of all brothers in a family to the same wife (fraternal polyandry) allows family land to remain intact and undivided . If every brother married separately and had children, family land would be split into unsustainable small plots . In Europe, this was prevented through the social practice of impartible inheritance (the dis - inheriting of most siblings, some of whom went on to become celibate monks and priests). </P>

When did western nations develop the idea that marriage should be based on love and last a lifetime