This book explores and assesses the multiple levels at which linguistic policies can be challenged, devised and enacted, i.e. sub-national, national and supranational, and the variety of state and non-state actors involved. Moving beyond descriptive and normative approaches, it provides an empirical comparative assessment of the policy responses and strategies deployed to deal with linguistic diversity and conflicts in Spain, a country where almost one third of the population is at least bilingual in their own languages. The Spanish case is then assessed within the European context, both from the perspective of multilevel influence and mutual interaction, and from the learning experiences it may entail for similar or equivalent problems and disputes occurring at the European level or beyond. This text will be of key interest to scholars and students of Spanish politics, linguistics, identity politics and more broadly of European politics and governance, public policy, education and communication policy and comparative politics.