While education research has explored the role of the principal in the advent of No Child Left Behind (2001), quantitative and qualitative studies fail to describe and explain the ways in which principals’ leadership practices are shaped by their conditions. These conditions include the school culture and climate in which they work; their own beliefs, skills, and understandings about leadership; and the actions they implement to achieve their goals. This article presents a conceptual model, resulting from a qualitative multi-case study, that demonstrates the need for—and benefits of—a more sophisticated approach to examining leadership in practice that takes up the psychological and organizational dimensions of leading in schools.