This chapter presents the history of International Business (IB) teaching at Harvard Business School and its impact on the teaching of (IB) broadly. Utilizing archival sources from the Harvard Business School and oral history, this study shows that contrary to current narratives regarding the history of IB teaching that suggest that it began in the early 1960s, there was a significant early history of IB teaching during the first part of the twentieth century that has not been fully recognized. Moreover, it argues that Harvard Business School faculty such as George Byron Roorbach, J. Anton Haas, and H. Hansen played pivotal roles in this fundamental period. Additionally, it suggests that the broader context of the Harvard Business School expansion and its level of international engagement were influential factors in this process. In addition, the chapter also describes the process that led to the dismantling of IB as a department at HBS in the early 1970s and comments on its implications for IB teaching around the world.