This paper explores how pre-service student teachers, in New South Wales Australia, integrate new global education into their existing disciplinary knowledge frameworks. Student teachers learning to teach secondary history and geography or business studies, or primary student teachers learning to teach society and its environment bring with them existing knowledge schemas based on their undergraduate disciplinary study, prior experiences and skills. It was hypothesised that new global education knowledge will interact with existing knowledge schemas in complex and interrelated ways. The paper reports on surveys of 204 pre-service students on the major understandings, concepts, skills and attitudes of global education. The paper finds that new global knowledge is additive to existing knowledge frameworks in various ways for secondary student teachers and integrative for primary student teachers. The paper explores the community of practice lens of subject discipline prior learning and the role it plays in the way student teachers respond to new subject matter. The paper discusses how disciplinary study integrates global education knowledge and identifies the implications of this for developing teacher education courses and for teacher professional development and learning.