Common six hundred years ago in the Christian world. Most noblewomen were married well before their 18th year. Edward I was IIRC 11 and his wife 13. They could be married to much older men, and women of higher rank could be betrothed even as infants.
Of course this isn’t six hundred years ago anymore either.
Somebody ring the alarm clock and wake these barbarians up to the modern world.
Practices such as polygamy and child marriage served a purpose in ancient societies, but that is not the case today. In todays modern world, women the world over should have access to education and true equal standing with men in the eyes of the law.
Um...yeah. So was dying in your twenties. That's the problem with a religion stuck in the 7th century, i.e. Islam.