Hi everybody,
So I'm writing a film with a friend of mine and the crux of the plot is that some form of apocalypse has occurred and the world is pretty much fucked. We're looking to set it roughly in 1300s Scotland. So I was wondering if there are any examples of Middle Age doomsday cults or collectives, or even an idea of what people expected from the end of days.
I've rented a couple of books on the subject, namely Apocalypse by JM Greer and a book on Celtic Mythology, but they're much more to do with our perspective based on what I've read.
Later medieval Christianity in the west was highly apocalyptic. From 1100ish on, essentially, most Christians paying reasonable attention would have expected the world was in the initial stages of the apocalypse. Some people thought it would take longer to finally end than others did, but you'd find very little classical Augustinian antimillennialism.
A couple of things you might consider. The Great Famine occurred across northwest Europe from 1315-1322; the Black Death was 1348-1351 with periodic waves of plague recurring after that. Those could be trigger events for wider chaos, if your "some form" of apocalypse is still brewing.
You might be interested in the collection of primary sources that Bernard McGinn translated for the Classics of Western Spirituality series, Apocalyptic Spirituality. It will give you some of the different ideas that various groups/authors had about the end times, which might set your mind going. I can point you to a few other groups as well, many of which would orient around a particular leader or prophet.
A couple things to keep in mind are that medieval Christians believed Antichrist was a real person/demon/entity who would oppose Christ; and a lot of groups (NOT ALL, emphatically not all) thought that the coming apocalypse would usher in an "Age of the Holy Spirit" (to complete the Age of the Father/Old Testament times; Age of Christ/New Testament through the Middle Ages times - trinity of ages). There was a LOT of conflict over different views of the apocalypse; lots of people excommunicated, even burned at the stake as heretics.
One note is that most of this is happening in the Italy-Germany-France triangle. Scotland is not as tightly tied into the intellectual currents of the university world yet, so I'm not sure how it would play out there. Still, the southern conflicts are tearing up England, at least.
I hope this is a good for a start. I can answer further questions, point you towards specific groups, or recommend further/more specific reading if you have some more sketched-in ideas of where you want to go with this. :)