King of the Stolen Lands
Basic Setting Information
This game is set in pre-Last War Eberron, in the region of Khorvaire known as the Shadow Marches. Since the Kingmaker Adventure Path is based in the Golarion campaign setting, all relevant geographic features, political entities, organizations, religions, and other pertinent elements have been modified or overlaid to fit within the context of the Eberron campaign setting. To further complicate things, the region of the Shadow Marches has been modified to contain the elements of the setting introduced in The Red Hand of Doom adventure. All of this can be rather daunting, so the best introductory reading for this adventure is the Kingmaker Player’s Guide, which is available as a free PDF download here.
With the basic knowledge from this text, you can explore the wiki to get a better picture of the turbulent nations of Western Khorvaire and the contemporary history of Eberron circa 800 YK.