Since its foundation in 1425, Leuven University has always been a transnational institution. Decentering Leuven University explores how this transnational character has shaped the university across six centuries, with cross-border ties emerging as a recurring theme throughout its history from the Middle Ages to the present day. However, these ties are more than just a recurring theme: they provide an innovative approach to writing university history. Taking the myriad cross-border ties as a methodological starting point makes it possible to view the history of the university from a new perspective. The rich variety of these ties highlights the complexity and diversity within the university. The author discusses, among other things, Leuven’s role as a center of European humanism in the 15th century, the significance of its Irish and Dutch mission colleges during the Counter-Reformation, the university’s more recent involvement in the Belgian colonial project, and the emergence of research institutes as hubs of transnational collaboration in the 20th century. Emphasizing these transnational ties leads to two forms of decentering the university’s history: it underscores the university’s embeddedness in a variety of cross-border networks, and it highlights the role of individual scholars, students, colleges, and research institutes in creating and maintaining these ties.