When researchers, textbook authors and teachers mediate historical knowledge, the representations tend to shift in different times and contexts. But how do different knowledge spheres interplay witheach other in the knowledge circulation in a specific society? The purpose of this paper is to examine the mediation of educational knowledge concerning the Christianization process in Sweden during theperiod 1915–2000, with the main focus on the relationship between the content in historical research and textbooks in history and religion for upper secondary school. The study will investigate the specific relation between 1) research publications in history, history of religion, archaeology, and 2) textbooks, in connection to a specific historical event. Through this, the paper will try and enhance the understanding of how the content in the texts can correspond and how this changes over time. The paper will utilize the concept of Knowledge arenas. The educational field and the research field will beperceived as two such arenas, where historical knowledge is mediated as a part of a larger infrastructure for knowledge. The analysis will be highlighting the intersection between historiographical and educational knowledge in the public sphere, which in turn brings new perspectives to the connection between the production and mediation of knowledge in the history ofeducation. The paper also brings the history of science into dialogue with the history of schooling, which can reframe our understanding of the social and cultural power over knowledge in education and its relationship to scientific development.