This article explores how beginning teachers develop their professional identities and knowledge. It analyses the stories of four student-teachers as they progressed through their pre-service programme and in their first year as primary teachers. During the three-year programme a range of instruments and a series of interviews were used to collect data on their developing subject and pedagogic content knowledge for teaching science, their teaching experiences, their views of teaching and of themselves as teachers. During the visit in school at the end of their first year as qualified teachers they were observed teaching their own classes and a final interview was conducted. The study examined the interaction between knowledge and identities, the extent to which specific subjects may be salient in their identities as general class teachers, and whether those identities were stable and coherent or shifting and conflicting. The stories extend beyond the four years of the study, drawing on the past and imagining futures, and they are analysed with reference to the concept of trajectories as used in relation to communities of practice by Wenger. Some implications are identified for supporting beginning teachers in their identity work and development of knowledge.