Preparing the analytical part of the book, this chapter provides an overview on the historic evolution of autonomy demands and statutes in each studied country. For Spain, it shows how sub-state autonomy developed at two moments: during the Second Republic for Catalonia and the Basque Country, and after the transition to democracy at the end of the 1970s for all autonomous communities known as of today. For the United Kingdom, the chapter reviews the Irish independence history and the particular situation in Northern Ireland to remind that the country’s devolution experience dates back far before the Scottish and Welsh mobilisation and conferral. It then goes on by discussing the incremental evolutions in Scotland and Wales, and their mutual influence. For Belgium, the federalisation of the country is put into perspective of the interplay of Flemish demands for cultural autonomy and Walloon demands for economic autonomy at the end of the 1960s. The peculiar situation of the Brussels-Capital region, in turn, is presented as the reason for the country’s federal structure with two different sub-state levels. Finally, it is shown how the German-speaking Community followed these dynamics.