This chapter explains how the formation of states, the territorial structure of government and its political–administrative organisation have co-evolved in Czechoslovakia and its two successor states, the Czech and the Slovak Republic. Inspired by Rokkan’s work on state and nation-building in Europe, the author adopts a longue duree perspective to trace the origins of current subnational territorial-administrative divisions in pre-1918 arrangements during the Habsburg Monarchy and their roots in early modern centre-periphery configurations. This historical and institutional context has persisted after Czechoslovakia’s transition to democracy in 1989 and subsequent disintegration, contributing to shape the (re-) creation of territorial-administrative regions and regional self-government in the late 1990s/early 2000s.