Purpose: While current research is reporting on a crisis in school leadership aspirations and appointments, this research sheds light on the mediating factors that school middle leaders (MLs) attribute to their appointment as a leader and their aspirations to senior leadership positions. Design/methodology/approach: Qualitative data from a larger, mixed-method, research project were collected using an online survey completed by 2,608 MLs in a large public school system in Australia and is analysed using an inductive thematic process. Findings: The findings suggest that MLs experience varying and non-linear career progressions and that a range of personal and professional factors impact their career aspirations. The support of an "experienced other" such as a principal, mentor or coach and strategic career planning are all important in the identification, support, development and advancement of MLs. Originality/value: This paper contributes to the scarce body of research on middle leadership identification and aspirations. The study recommends a system approach drawn from the empirical data and associated literature that may be useful to inform policymakers, school systems and school leaders in efforts towards middle leadership identification, development and advancement.