Well, there's never been a matriarchal society, so I don't know that we'll ever know for sure. Also, there's no evidence of large scale violence before about 10k years ago.

An Ancient, Brutal Massacre May Be the Earliest Evidence of War

But since that time, when the other social mechanisms of more egalitarian cultures for keeping the peace started to break down, it is more difficult to keep aggressors at bay without being able to show some force.