As secondary school environments become increasingly complex, shifts are occurring in the way leadership is being practised. New leadership practices emphasize shared or distributed leadership. A senior executive leadership team with responsibility for school leadership is likely to be one of the many, varied forms of new leadership practices adopted in secondary schools. However, research has shown that many teams do not reach their potential and many more fail. Therefore, the purpose of this exploratory study was to investigate the processes that underlie senior executive leadership team performance and effectiveness. A multi-case study design was used. Three randomly selected senior executive leadership teams from government secondary schools within the Sydney metropolitan area, in New South Wales, Australia participated. Data were obtained from individual, digitally recorded face-to-face semi-structured interviews. The findings from this exploratory study suggest that complex environmental events necessitated a shift from single leader to team centred leadership in these three schools. Principals in the study played a critical role, fulfilling the role of team leader, and applying leadership functions flexibly to enable team development, management and effectiveness. Further, the results provide insights into the innate complexity of leadership conducted synchronously by a collective. (Contains 1 table and 1 figure.)