Philosophiae Doctor - PhD / This thesis investigated the leadership approach associated with sustained improved academic performance of principals heading National Strategy for Learner Attainment (NSLA) schools. The research problem addressed the leadership practices and personality traits that characterised the leadership approaches of principals heading high schools which have achieved long-term academic improvement amongst the schools undergoing the NSLA interventions. The main research question was: What leadership practices and personality traits characterised the leadership approaches of principals heading schools who have achieved long-term academic improvement amongst the schools undergoing the NSLA interventions? Thereafter, four subsidiary research questions guided this research.