This book focuses on territorial policies as instruments for local development in Europe’s periphery. Using a multiple-case research design in three typical case studies in the context of the Mediterranean island of Sardinia (Italy), we empirically test the hypothesis that the institutionalisation of the governance system is an independent variable that is capable of influencing the quality of public policy, intended as a dependent variable. According to this hypothesis, the two above-mentioned variables tend to change according to a linear and direct correlation: upward variation of the degree of institutionalisation of the governance system tends to correspond to upward variation in the quality of the policy, and vice versa. In our conclusions, we discuss the descriptive and prescriptive implications of the empirical findings of the research for the local development of peripheral areas. Regarding the descriptive implications, we explain how territorial policy-making can be articulated, based on the degree of institutionalisation of the governance system and the quality of the territorial policies. Regarding the prescriptive implications, we identify the best practices for territorial governance in order to improve the chances of local development in Europe’s periphery.