Linguistic fragmentation contains the risk of cultural separation, while the concept of inclusion implies the recognition of the difference of the Other, who must be recognised in its specificity to develop a process of inclusion. One of the main means of overcoming the dangers hidden in linguistic fragmentation is unquestionably plurilingualism and, relatedly, translation. Translation enables the transmission of content from one linguistic-cultural system to another. Multilingualism is not just a peculiarity of the contemporary age; it is a fundamental phenomenon of the Middle Ages. The conceptual relationship between linguistic fragmentation and cultural inclusion, and the inter-relationships of these two apparently opposing poles with the communicative tool of translation, requires some reflection within the broader framework of translation studies in the Middle Ages. This collection of essays examines the seemingly paradoxical concept of linguistic fragmentation as an instrument of cultural inclusion thanks to the practice of translation. The essays explain the relationship through translations between many medieval languages and texts, from Icelandic to Italian, from English to French, and more. They examine vernacular circulation of religious texts (translation of the Bible, of hagiographic or homiletic texts, etc.); circulation, thanks to translation, of literary texts (e.g., the translation of epic-chivalric cycles); translation from a koine language to another language and vice versa; and the relationship between the choice of the target language and the socio-cultural context.