As different thinkers, Engels among others, have already stressed, polygamy is the trait of no single people; it has been and continues to be practiced by the upper classes in all countries, perhaps not in different degrees, but in different forms. It was customary among the German aristocracy of the time of Tacitus, in Greece at the time of Agamemnon, throughout the whole of Asia and in Egypt among the family of the pharaohs and the dignitaries of the court. In all these countries, without damage to the existing morality, this luxury was open to anyone if he had the means,
but monogamy was the rule at the level of the mass of the people, particularly in Africa. In so far as Africa is considered to be the land of polygamy, it is important to emphasize this fact. In sculptural and pictorial representations, the monogamy of the people is proved by the numerous couples depicted.
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It seems that this was so in all Africa during the late Middle Ages, until the tenth century, which marks the extension of Islam to the native populations, through the Almoravidians. Polygamy tended in this way to become general, without ever ceasing to be a sign of social rank. Thus, it is not rare to see members of the lower classes who, seeking to deceive themselves about their own social rank, marry several wives.