The ‘holding-together’ federations of Western Europe- Great Britain, Spain, Belgium and Italy- have confronted the tension between accommodating the autonomy claims expressed by regionalist parties and preserving stability in the territorial structures of the state. This paper employs the tools of comparative historical analysis (CHA) to examine how this tension is managed by partisan actors during the evolution of state structures. The paper first puts forth a conceptualisation of territorial restructuring as an asynchronous and open-ended development that can nevertheless be delineated temporally into distinct moments of transformation. It then looks at the drivers and timing of constitutional reform, by focusing on the role of regionalist parties in setting the agenda and forging coalitions with Social Democratic parties and on the role of centre-right parties in preserving the status quo. The third part examines how the tension between accommodation and stability is managed during the ‘critical juncture’ surrounding the creation of regional structures of authority, highlighting the importance of historical precedents in shaping the templates of partisan actors and the range of institutional choices. It then looks at subsequent ‘reactive sequences’, by examining how mainstream parties adjust their preferences with respect to the structures of state, and how this affects the mechanisms of constitutional reform, the salience of different policy areas and the sequencing of decentralisation. The final section examines sources of institutional entrenchment and the incentives for vertical and horizontal cooperation between partisan and territorial actors.
