God ordained that marriage be sacred, but he did not prescribe the number of wives, neither a high nor a low one. He commanded: thou shalt be faithful to thy marriage vow, and though shalt not break it. Now it so happens that God has always created many more women than men. And He makes men die more readily than women. And He always lets the women survive and not the men … And if there is such a surplus of women, let it be taken care of by marriage, so that the meaning of God’s commandment may be heeded … If this cannot be achieved by giving each man one wife, she should have two, or whatever number may be required to take care of the surplus.

Phillip Von Hohenheim (1493-1541)
Cited by George H. Williams, The Radical Reformation
Westminster Press, 1962, p. 509