This paper brings a unique, longitudinal perspective to the field of teacher identity by extending on Lave and Wenger's (1991) notion of legitimate peripheral participation to theorise the relationship between teacher identity and agency in multiple and temporal practicum contexts. This study examined eight pre-service teachers in three teaching practicums over a three-year period. Findings reveal that each pre-service teacher became 'identity brokers' by employing agentic tools to affirm and maintain their identities within multiple practicum contexts. These agentic tools included demonstrating situated knowledge, codes of practice and establishing a system of relations with old-timers in each practicum school in order to gain legitimacy as a newcomer. In doing so, this paper demonstrates how legitimate peripheral participation offers a new way to theorise the complex and nuanced relationship between identity and agency in multiple and temporal contexts.