The aim of the project is to empirically describe the historical colloquial language of Mecklenburg on the basis of a comprehensive, in part novel database. The focus is on the structure and dynamics of this historical region around the middle of the 19th century, with a diachronic perspective being added to the research focus by looking at the subsequent 20th century and the preceding turn from the 18th to the 19th century. To this end, a corpus of literary and language didactic texts from the 19th and late 18th centuries was compiled. The diatopic perspective on the 20th century and the beginning of the 21st century is achieved by analysing the relevant research literature, including the information in Dahl (1974), Kehrein (2012), Ehlers (2018/2022) and the first volume of the ‘Nordeutscher Sprachatlas’.