It was a great economic and social strength of Judaism, as opposed to Islam, that it rejected polygamy. The Pentateuch did not actually prohibit it, but Proverbs 31:10–31 appeared to uphold monogamy and it was the rule from post-Exilic times; from the age of Rabbi Gershom (960–1028), bigamy and polygamy were punished by the severest type of excommunication in European Jewry.
