This dissertation examines how principals in Swedish schools interpret and develop strategies for action within the tension between the ideal of inclusion and the demands of organizational and pedagogical differentiation. Grounded in a systems and neo-institutional perspective, the dissertation conceptualizes principals' leadership as a meaning-making and institutionally embedded process, in which interpretation, negotiation, and action are shaped in the encounter between structural conditions and professional values.

The dissertation draws on five sub-studies that illuminate how principals' leadership is constituted across different levels of the education system: policy and text analyses, conceptual-historical policy analysis, systematic literature reviews, and interviews with principals and other actors within governance arenas. Students with autism serve as an analytical example, foregrounding how the tension between inclusion and differentiation takes concrete shape in practice and why both school leadership and special education perspectives must be held together.

The cover essay applies institutional logics and sensemaking as analytical lenses to examine how policy signals and governance expectations are interpreted and made meaningful in principals' everyday leadership. The findings show that leadership can be understood as a continuous process in which policy and governance are translated within local contexts, forming the basis for developing strategies for action. These strategies constitute ways of managing competing institutional demands while simultaneously reshaping the conditions and scope for principal agency. Leadership thus emerges not as individual choice, but as an ongoing process of interpretation and negotiation within, and in response to, institutional frameworks.

The dissertation makes two interconnected contributions. First, it advances understanding of how systemic and institutional conditions shape principals' interpretive work and strategic action. Second, it bridges school leadership research and special education research, two fields that have largely developed in parallel despite addressing the same organizational challenges. By analyzing inclusion and differentiation as questions of leadership as much as pedagogy, the study demonstrates that decisions about placement, resource allocation, and school organization cannot be adequately understood without attending to the institutional logics and governance conditions within which they are made.