Medieval: 1 000 years, give or take a few. Assuming we only focus on Europe: 10.18 million square kilometers with over 200 languages (much, much more if we count regional dialects).

You will have to be a LOT more specific to get any answers - I focus on 1250- 1350 Hungary, and there are some major differences in fashion there depicted in one chronicle only (about 6 different hat types, to start with), and that's not even going into the fact that different people likely preferred different things.