In many European universities today, national languages and English are used alongside a plethora of other linguistic resources. Our volume provides a response to changes in higher education where internationalisation and widening participation not only pull towards the use of one shared language but also increasingly diversify language practices. How are different languages experienced and perceived by university stakeholders? After clarifying a number of key concepts, we show how different chapters unveil the tensions arising between monolingualism and multilingualism and chart the multiplicity of language perceptions and practices across the university, from education and research to administration. The educational contexts explored here include Sweden, Finland, Denmark, Iceland, the Baltic states and the Netherlands.