A lecture by Dr. Futuro, part - time London Sexologist - (open to charity cases if you are young).
Marriage started long ago.
Unfortunately, We can't start with Adam and Eve as they weren't married - just shacked up together - (all they had were shacks, back then).
In the Old testament - God allowed the Patriarchs to have as many Wives as they could afford. Also Concubines and servants for occasional sexual variety. God was very generous to the Patriarchs.
Then we zoom forward to Modern times. Rich Men can only have one wife at at a time - but over a life time can have multiple wives - just as in the Bible.
They can also have Concubines, now called Mistresses - and still have sex with the servants - (witness Arnold Schwartzenegger having a son with his housekeeper).
But you keep hearing ignorant religious people saying.. 'Marriage is between one man and one woman - and for a lifetime'.
Where does it say that?
Don't they ever read their Bible?