Organisational coup d'état is a radical mechanism of strategic change. Unlike other forms of discontinuous management, they are triggered by deep-seated internal grievances and so are likely to trigger sensebreaking and reinterpretation of organizational narratives. However, almost nothing little has been written about them since the term was introduced almost forty years ago. We remedy this by developing a process model based on an in-depth case study of a 2014 coup as it went through three phases: tension building, confrontation, and alignment. Our findings challenge many previous assumptions about organisational coups d'état as our case demonstrates that they can be driven by non-directors, contain multiple agendas, replace whole boards, and lead to significant strategic realignment. Our findings primarily contribute to the strategic change literature.