This contribution attempts to problematize the concept of vernacularization during the Western Middle Ages. Taking modern research on endangered languages as its point of departure, it distinguishes between two periods of vernacularisation, the earlier one determined by the desire to standardize vernacular writing (literization), the other one by a factor of literarization, i.e., creating a literary language and field. In both periods, Latin as the hegemonic language constitutes the catalyst for these processes as they develop within the vernacular field.