Like Karl Popper in The Poverty of Historicism does with social science methods going by that name, this paper points to territorialism as a misguided way of dealing with contemporary issues. First it makes the case for territorialism. It implies the control of people and resources by controlling area, what is called “territoriality”. Under territorialism and the crisis of the European Union the paper shows that this crisis raises questions about what the Union is and should be. The prevailing answer of strengthening nation states may lead to its disintegration, Jan Zielonka argues, but disintegration will not lead to the expected resurgence of nation states, themselves epitomes of territorialism. Pursuing the neo-medieval alternative, this paper reports on the same author foreseeing overlapping territorial and functional arrangements, like in an empire. The next part discusses spatial planning in the neomedieval empire where European space must no longer be seen through the lens of territorialism. Rather, it should be viewed as overlapping and intersecting areas, each requiring its own governance. The implication for European planning, true also for strategic planning generally, is to abandon the pursuit of spatially integrated policies. Instead, planning should produce parallel and overlapping schemes for various territorial and functional spaces.