Yes, it was (and some places, sadly continues to be) the ultimate horror that people can visit upon each-other.

Suffering it, over and over and over, was what led humanity down the natural, logical path to becoming civilised and cooperative.

It's the lesson we need to learn well, if our self-appointed badge of Very Intelligent Species is to actually mean anything more than a pointless, neverending game of forming factions and battling other factions.