This idea is really Dave Margowsky's, but I wanted to present another idea for a game world.
Imagine a fantasy setting where all the great empires of the world, co-exist. Now. Obviously not at the apex of their geographical boundaries, but rather at their cultural nexus. Eqyptian gnolls, Roman humans, human or goblin or orc Germanic tribes, human Celts, human Goths, Trojan elves, Spartan elves, Persian dwarves, Mongol orcs, Turkish orcs, Norse dwarves, Spanish Inquisition elves, Anglo-Saxon orcs, Phonecian elves, Viking orcs, Russian (Novgorov and Kiev) dwarves, Norman humans, Prussian dwarves, Ottoman elves, Magyar orcs, Carthagianians... perhaps as elves, and Macedonian elves.
Not to mention Manchu, Tang, Khmer, Dravid, Hindi, and Aryan races... perhaps as demi-humans with little association to the West.
Altogether, these nations would comprise Asia minor and Southern Europe. Each nation would emulate the cultural standards of their real-world equivalent, while not extending their borders (initially) beyond the borders of their neighbors... this would make Greece, for instance, very crowded. However, once play began
DMs could use the Diplomacy or Risk boards to emulate large scale battles that affect all of the "natives." At the end of each session, entire armies could move, shifting the boundaries of game play, affecting the PCs on their level, while allowing the players to impact the game on another level.
Anyway. Just sketchy notes for the time being.