This article describes the work of the school principal in building a vibrant learning community for staff and students. The descriptions emerged from a series of investigations into teaching, learning, and leading practices within schools that have high capacity for effective teaching and learning. These investigations demonstrated that the direct and consistent involvement of the school principal is essential for building a culture of learning for staff and students. In successful schools, principals serve four broad functions: center, holder of the vision, builder, and role model. These roles yield cultures and structures that sustain, energize, and vitalize teaching and learning.