This study describes an aspect of school-based management that previously has been ignored. Drawing on concepts from an institutional theory of organizations, this study describes the actors who shaped and promoted school-based management in the national arena, their interests, and the network that linked them. Three categories of actors are identified: policy actors, teachers union actors, and academic actors. The most prominent actors were often organizations rather than individuals. The actors shared two overarching goals: to improve the effectiveness of public schools and enhance the professional status of teachers. The actors were linked by an informal network; that is, they were loosely organized. These and other findings suggest that school-based management was at least partially the product of the institutional environment in which schools and school districts operated.