Berlin is an ancient city. Dating back to at least 1192 AD., if not earlier. Berlin has been the capitol of the kingdom of Prussia, The German Empire, The Wiemar Republic, The Third Reich, and while divided during the cold war, is now the capitol of the Federal Republic of Germany.
While the normal city is very populace, the shadowed portions are far more so, Making Berlin a MegaCity in more than simply name. Large sections of the city are overlaid with potent energies that allow for the simultaneous existence of one or more parallel buildings, streets, or even entire city sections. This additional space is where nearly all of the veiled and shadowed activities take place, with heavy restrictions on anyone moving beyond them. Nearly the whole of the city has some sort of shadowed overlay, allowing an entity to visit almost the whole city without setting foot in the mundane.
Berlin is well know to have been a shadow city for a very long time, possibly since before its historical founding. While little is known for sure, it is thought that after the fall of the roman empire many of the deposed and displaced houses fled, eventually ending up in Berlin hundreds of years later. Berlin has since been a destination for exiled and deposed houses, nobles, and royalty. As such Berlin is a highly political city, so much so that the shadowed sections function as one enormous royal court, with as much intrigue as a few thousand years of displaced royalty various houses can possibly create. As such anything that does happen does so slowly; due to the combative nature of the various powers in play.
This is complicated further by the major draw of Berlin, the vast accumulation of diseased spirits, and the ethereal chains that bind them. For reasons unknown or lost, Berlin is permeated with chains of various thickness, binding many of the dead and some of the living to the city. This means that a successful assassination can mark the beginning of a politicians career, rather than the end. The vast patience of the dead results in a political environment where a well planned maneuver can be executed over generations of mortal lives, adding vast new layers to the wheels of intrigue and diplomacy.
Notable factions within Berlin: