This article reports the findings from an ongoing evaluation of a new model for collaboration among secondary schools: the Birmingham Collegiate Academies. The claims the authors make in this article are based on two years' field work and draw on individual interviews and more informal discussions, attendance at meetings of headteachers and other staff, and the analysis of documents and examination results. The authors have also used an analytical framework developed by Connolly and James (2006) that identifies two quite different perspectives on schools' reasons for collaboration--to seek additional resources and to enhance institutional legitimacy--to help them analyse the data. (Contains 1 table.)