Matt Colville's video on Diplomacy inspired what has been my favorite DMing endeavor: using a game of Diplomacy with your players to create the history of the setting.
First, pick a map to play. I recommend playing on VDiplomacy.com as they have a large variety of maps to play supporting 2 players up to 50. I chose Sail Ho II, seen below.
Next, assign characters or races to the factions. For our game: West was Dragons, North was 'Gods', East was Amazonians, South was Giants. If you wanted to go for a smaller fantasy dynamic, you could go Orcs, Elves, Dwarves, and Humans, or any other creatures/races/factions that you want to establish as players in the steady-state world.
Once you've assigned the factions, start playing. I highly recommend playing in character. Our game had some gems like:
When the game is over, you'll have a map showing the different factions, and their regions and control, as well as several still neutral regions that can represent the frontier.
And voila! You now have a world map with a history your players are interested in because they made the history! You may even find that players make characters allied to the faction they played as, creating an awesome opportunity for drama.
And for extra credit, you can do what I'm about to do in my next series of post: track all of the units year by year and make them into NPCs or characters from ancient myth and legend, depending on when you set the campaign in relation to the war.
