The idea of school leaders working beyond their school context is nothing new. In many countries, leading within and beyond schools is central to system change and renewal (Chapman Citation2019). The core idea is that considerable value is added to the system when experienced and effective leaders move beyond their immediate role to build relationships and forge new impactful links with others. It has been proposed that system leadership implies a capacity-building model that encourages those leading at different levels within and across the system to generate innovation and change (Fullan Citation2025). Within the literature, system leadership is conceptualised as lateral or distributed leadership that is not driven or dictated from above but grows organically through various forms of partnership, collaboration, and networks. But where did the idea of system leadership come from, and what does the evidence tell us?