Universities in Denmark are becoming increasingly internationalized, and areincreasingly using English as a language of research, teaching, and administration. At the same time, the Danish language is seen by some as being under threat, and Danish public discourse has focused on what role the Danish language may play in higher education in Denmark. This study investigates both trends through a focus on recently implemented language policies at one Danish university faculty which mandate that graduate instruction becarried out only in English, and undergraduate instruction only in Danish.This study investigated the decision making process over time in order to reveal how such language policies would be received in one affected department. Interviews with department teaching staff were carried out both before and after the implementation of the decisions, along with interviews of department and faculty level leadership, classroom observations and analysis of written documents. Data was organized using the model provided by Innovation Theory (Henrichsen, 1989), and interpreted using the discursive framework of Nexus Analysis (Scollon & Scollon, 2004).Analysis showed how case department teaching staff used English and Danish, and how they oriented to the case decisions. Findings indicate a mismatch between top-down policies which do not take into account how language is used on the department level, and an increasingly international department characterized by a predominantly bottom-up approachto determining language use. This research has implications for other institutions which are affected by similar language issues. It adds to existing work on English-medium instruction in higher education, and adds to discussions on domain loss and the language of education inuniversities.