Jay Michaelson delivers some inconvenient news to those who claim that marriage has always meant one man committed to one woman:
Time to break out your Bible, Mr. Perkins! Abraham had two wives, Sarah and her handmaiden Hagar. King Solomon had 700 wives, plus 300 concubines and slaves. Jacob, the patriarch who gives Israel its name, had two wives and two concubines. In a humanist vein, Exodus 21:10 warns that when men take additional wives, they must still provide for their previous one. (Exodus 21:16 adds that if a man seduces a virgin and has sex with her, he has to marry her, too.)
But that’s not all. In biblical society, when you conquered another city, tribe, or nation, the victorious men would “win” their defeated foes’ wives as part of the spoils. It also commanded levirate marriage, the system wherein, if a man died, his younger brother would have to marry his widow and produce heirs with her who would be considered the older brother’s descendants. Now that’s traditional marriage!
I would add that even in modern times, “marriage” means serial monogamy–being committed for life to one special person, until you get tired of that person and then move on to being committed to a different person forever.