Plural marriage has always existed so long as there have been human beings around. And although Lamech is the first recorded man to have had more than one wife in the Bible, there is no reason to suppose that there were not many others before him. The reason the nation of Israel multiplied so prodigiously during the Egyptian captivity was because of plural marriage. Their rapidly increasing numbers, even during the wilderness wandering, gave them the ability to populate the land of Canaan when the natives were displaced.
The elimination of plural marriage from Christianity was gradual and continued unopposed for at least three centuries after the New Testament period. By the fourth century the emerging Roman Catholic Church, which had, and was continuing, to persecute (often to the death) any opposing creeds to its own, had started enforcing celibacy on its clergy. The pressure was being felt on the lay people as well. Though fewer and fewer were by this time living in a plural arrangement, it is known that one common arrangement was for a man to have one full wife and a concubine but by the turn of the fifth century even this was declared to be criminal. Priests who were married were forced to declare their marriages null and void and by the seventh century plural marriage was officially outlawed by the Roman Emperor Justinian.
Sporadic polygyny did appear in Europe and was tolerated by the Catholic Church, especially in times of war when the male population was decimated. Not until the 16th century did polygyny become a capital offence. When in the 18th and 19th centuries Europeans started evangelising Africa, it was not long before monogamy was imposed on converts and polygamous families were forced to break up. In spite of the opposition of many local ministers who argued that plural marriage should be tolerated, the upper hierarchy always vetoed such suggestions until the 20th century when the Catholic and many Protestant Churches began turning a blind eye so long as polygamous husbands did not contract further wives after their baptism.
Plural marriage did not surface in the West again to any great degree until the Mormons began the practice in the 19th century in America. It earned them persecution from Catholic and Protestants alike and they were officially forced to abandon it at the end of that century. Its secret practice continued underground leading eventually to a schism between the mainstream Mormons and the 'fundamentalists' (FLDS). Probably about 50,000 claiming Mormon roots practice this lifestyle in the United States today.
Though no doubt there have always been a tiny handful of polygynists in Europe they did not surface until the end of the 20th century, in the 1980's, under my own ministerial leadership. A decade later polygyny ministries began to appear in the United States and elsewhere too. In the space of a decade increasing numbers of Westerners have been drawn back to full biblical marriage and at last polygynists in Africa and Asia, who were always right about this divine lifestyle, are once again being accepted into churches and assemblies who not only accept but actually proclaim the lawfulness of plural marriage.
As far as marriage is concerned, there can be no doubt that the West went through a 'dark age' every bit as dark as the political equivalent under the Catholic tyranny. Slowly but surely that is beginning to change. It is probably true to say that few, if any, of the extant denominations will accept plural marriage, though more may tolerate it. A few, like ours, with an apostolic mandate, are nurturing it especially in Africa and Asia where it is normal.