Among western governments large-scale leadership development initiatives represent an increasingly deployed means of promoting the acculturation of school leaders to support educational reforms and ongoing improvement. England’s sophisticated initiative centres on the National College for Leadership in Schools and Children’s Services, a politically driven intervention to acculturate headteachers and other senior school staff into transformational and distributed leadership. It is linked in significant measure to government-driven reform, alongside continuous improvement efforts. Qualitative research whose focus included tracking the evolution of this initiative showed how moderate mediation, within broad structural and ideological limits, is integral to its implementation. The fostered leadership culture appeared to interact with recipients’ existing organizational and wider professional cultures valuing a substantial degree of local autonomy, stimulating reinterpretation and adaptation. Yet mediation appeared ultimately to have supported the government’s agenda through local adaptation of reforms and some independent innovation consistent with the reform thrust. Contemporary government policy is to promote innovation, but the continued retention of nationally set expectations, strong accountability measures, and heavy sanctions seem likely to limit its potential for promoting locally inspired educational improvement.