u/KalissaExplainsItAll

I know upside down crosses appear in many horror films, but I’m trying to think of what film explains that originally the upside down cross was a Christian symbol. One character is explaining to another that Saint Peter asked to be crucified upside down as he felt he was unworthy to be crucified in the same manner as Christ. All I have is a vague recollection of learning this fact from a film, but can’t recall which one. Any help would be much appreciated!