Matriarchies in History: Khasi, India (40,000 years)

As of 2011, this matriarchal society was comprised of about 1 million. Mothers and mothers-in-law are the only people allowed to look after children and, according to The Guardian, men aren't even entitled to attend family gatherings. What's more, when women marry in the Khasi tribe, their surname is passed down instead that of their husbands.