Sure Start, the national initiative created in 1998 and implemented through local programmes, sought to improve the life chances of children living in areas of deprivation. Children’s services were to be ‘joined up’ to deliver new and different ways of working. The inclusion of teachers was integral to some programmes, although little research was available to document this. This study sets out to examine how teachers responded to the challenge of promoting babies’, toddlers’ and young children’s learning within a multiagency and community context. It investigates how teachers’ roles were constructed; the nature of their everyday activities, how they responded to multi-agency work; how innovative work arose and what triggered change. Qualitative and ethnographic in nature, the study incorporates empirical evidence from six Sure Start Local Programmes (SSLPs). Research methods were designed to access teachers’ thinking within a situated perspective. In addition to work shadowing and scrutiny of documents, data was gathered from 25 semi-structured interviews with team members, managers and teachers. Three complementary theories of social learning; Activity Theory, Communities of Practice and Professional Craft Knowledge, were brought together to interpret findings. Teachers demonstrated varying levels of participation within SSLPs. Those moving towards full participation had undergone identity transformation, and contributed to the construction of a new practitioner: The Sure Start Teacher. Through engagement in front-line joint work with practitioners from other agencies, expansive learning has occurred and this in turn has stimulated innovative practice. The role of teachers in SSLPs can be described as: exchanging knowledge and skills within a multi-agency team; facilitating intergenerational learning in the locality and providing a pedagogic lead within a framework of joint work with members of the Sure Start community.