In this ambitious monograph, Manzini organizes and clarifies the voluminous evidence that exists on local dependencies according to a single, unified theory of Locality. Locality is a simpler and more comprehensive alternative to the barriers approach, the antecedent-based approach, and the connectedness approach, subsuming all the major locality principles (Subjacency, ECP, and binding theory) invoked in the other approaches and explaining a set of islands that remain refractory to those approaches.The first chapter defines the empirical problem and provides an overview of the solution; it also introduces the three main alternatives to Locality theory. The second chapter presents Manzini's theory in detail and includes a unification of Subjacency and the antecedent-government clause of the ECP and a unification of the ECP internal disjunction between the antecedent-government and the head-government clause. In chapter 3, Manzini argues for the empirical superiority of Locality, offering data predicting that Complex NP islands, Tense islands, and Definiteness islands all belong to the same fundamental type while multiple WH-islands reflect the fact that at most two overlapping extraction paths are available at any given point in a derivation. The final chapter looks at binding, showing that it can be accounted for under the same Locality principle as movement but without the need for anaphors to move at any level of representation.