This paper arises from the International Teacher Leadership (ITL) initiative which explored the potential of a non-positional approach to teacher leadership for educational and social reform. The ITL approach does not rest on traditional assumptions about organisational structures and patterns of authority. The focus is on the ‘work of leadership’ (Heifetz & Laurie, 1997) or ‘leadership practice’ (Spillane, 2006) rather than on the attributes of designated leaders. The ITL methodology was a form of action research featuring structured discourse and the exchange of narratives across cultural boundaries. Local teams in each of the 14 countries (for example Croatia, Serbia and Turkey) collaborated to create programmes of support for teacher leadership. These were evaluated in action using qualitative data collection tools selected from a common toolkit. The dialogic nature of the process addressed the hazards of ‘policy borrowing’ (Philips & Ochs, 2003; Steiner-Khamsi, 2004). The ITL initiative has contributed to what we know about strategies to mobilise teachers’ sense of moral purpose in order to improve professional practice in a wide variety of educational systems. It provides evidence to support a theory of non-positional teacher leadership and illuminate strategies to support it.