If I were to write a large scale war piece which required elaboration on the main factions' current territories, roles and a basic history as well as a quick tidbit on how the current warfighting method came to be. Thing is, all I really need is a rough overview of where the factions are, what they contain and what happened to cause the events currently happening. The story itself only takes place in one city, this is all backstory. Should I draw up a timeline and paste it near the beginning as in: In month y of year x, faction z did a and had impact b on area c. That sets everything up correctly, in order and shows a detailed progression of events but is a lot to digest at once and most people won't bother to remember it all. Or I could leave an author encyclopaedia at the end with all the needed details about factions, doctrine and such. This means readers go in blind and have nothing really to go on and have to leave the story and page through a load of expo to find info on what these guys do. The third option I can think of is having characters or events reflect on and mention previous happenings like people musing about how they got to this, explain a particular event which bought this design along and/or explain a faction's effects on the world through character opinions and chats. This doesn't really yank a reader away from whats occurring so they can look for details, but if they want to know something, there's no single place they can go to so they can find all they need on a particular subject. Ideas?