Clean Break Theatre Company is a women-only theatre company that grew out of a prisoner-led drama workshop that took place between 1977–1979 in HMP Askham Grange. In addition to its considerable impact on criminalised women and public understandings of the socio-political impact of their experiences, Clean Break has had a significant but under-acknowledged impact on contemporary British theatre. We examine three areas of Clean Break's theatre making history and organisational practices: its origin stories; its education and engagement work; and how the company's performance practices have, across five decades, 'then' and 'now', adapted to directly intervene in carceral society. By highlighting Clean Break's distinct activist theatre making processes and practices, the book makes explicit the genealogical connections of the company's past work and its impacts on contemporary feminist theatre practices.