Board Thread:Speculation House/@comment-14138255-20140822003454/@comment-24435688-20140822044102

I don't think that humanity in Remnant predate the Grimm since Cortana also says that they were born (typically a word associated with beginnings) into a cruel world.

It's possible that the Grimm weren't a major threat at first and humanity managed to have a semi-decent existence before they got out of hand and decided to genocide everything. For all we know, the Grimm could work like climate changes in our world: the go from one extreme to the other over the course of a very long time and nobody has any idea what's happening during the extreme periods.