Labash is a campaign based on ancient Lebanon. It's pre-Islamic, pre-Arab, pre invasion of the Syrians or the Egyptians. It's back far enough that we don't have ready cultural references to play upon. Yet, the geography and nearby civilizations make it easy to model a campaign after history, at least a poor recollection of it.
From a DM's perspective, this means I have to work less hard than creating a campaign world from scratch, but harder than if I just grabbed one off the shelf. For much of the campaign, I'm changing the names and borrowing from various periods of history in the same region to come up with events. This has worked very well in the past for me, even mixing historical peoples that never co-existed together.
From a player's perspective, you'll be playing straight D&D, 4th edition in this case, without cultural reference points. You won't see Middle-Eastern cultures as you generally know them. You also won't be seeing a straight European medieval setting. We're aiming for something several thousand years old that appears culturally neutral.
For those not playing in the game, please excuse the historical inaccuracies and cultural insensitivity as I generally mix and match modern day Middle-Eastern politics and events from several thousand years ago.