I especially enjoyed seeing how WW1 changed the world/British society. Everyone economized and made do with less "because there's a war on" and pretty much never looked back. So huge manor staffs became... smaller. And that was ok, because the wealthy that needed to change for dinner ... didn't. Because there was a war on, and materials were harder to get and it felt -wrong- to try. And you didn't have the staff anyway. So rather than formal wear you were merely.... clean. And it turned out that was FINE.