How would a medieval society fight monsters?

I was thinking pikeman and crossbows from bigger monsters but what's your take on the idea. Would you use knights like in story's or maybe artillery I don't really know the best way and I'm open to your ideas.

I'm looking for just general ideas on how they could fight monster really anything because I'm seeing what tatic people think would be affective before putting monsters in. There could be big monsters like Dragons and giants or there could be small monsters like swarms of ghouls I'm trying to get a general gist