Board Thread:Speculation House/@comment-4010415-20140802105040/@comment-14909251-20140811172449

I imagine that Menagerie was basically like an Indian reservation. Faunus were forced there by the human population from their original lands. They probably had some sort of military presence to keep the Faunus from breaking out of the area, but there were likely many living outside Menagerie still and maybe even those whose presence outside Menagerie was tolerated. I suspect the war erupted due to a major push to relocate the Faunus populations that still lived outside Menagerie.

My own theory is that the Faunus are the original inhabitants of Remnant, with humans being relatively recent arrivals who begn forcing out the Faunus. It is possible the Faunus are also able to live more peacefuly amongst the Grimm than humans due to them not being humans and their own natural advantages, prompting its own form of resentment. Perhaps Faunus were perceived as being Grimm-like or in league with the Grimm due to their ability to live sustainably among the monsters.