Polygamy is still common across much of the Muslim world.
The idea of marriage as a sexually exclusive, romantic union between one man and one woman is a relatively recent development.
But when the empire collapsed, in the 5th century, church courts took over and elevated marriage to a holy union.
As the church's power grew through the Middle Ages, so did its influence over marriage.
To marry for love without land or chattels could assure nothing but a life of penury. Not all young people, however, had marriages arranged for them.The parents and siblings in the families had a concern in the marriage, and the lord also wished to keep some accounting of village marrieages.