This project uses corpus linguistics and geostatistics to test the sociolinguistic typological theory put forward by Peter Trudgill on the history of Norwegian. The theory includes several effects of societal factors on language change. Most discussed is the proposal that ‘intensive’ language contact causes simplification of language grammar. In the Norwegian case, the claim is that simplificatory changes which affected all of the Continental North Germanic languages (Danish, Swedish, Norwegian) but not the Insular North Germanic Languages were the result of contact with Middle Low German through the Hanseatic League. This suggests that those simplificatory changes arose in the centres of contact with the Hanseatic League: cities with Hansa trading posts and kontors. The size of the dataset required would have made it impossible for previous scholars to test this prediction, but digital approaches render the problem tractable. I have designed a 3.5m word corpus containing nearly all extant Middle Norwegian, and developed statistical methods for examining the spread of language phenomena in time and space. The project is made up of a series of case studies of changes. Three examine simplifying phonological changes: the rise of svarabhakti (epenthetic) vowels, the change of /hv/ > /kv/ and the loss of the voiceless dental fricative. A further three look at simplifying morphological changes: the loss of 1.sg. verbal agreement, the loss of lexical genitives and the loss of 1.pl. verbal agreement. In each case study a large dataset from many documents is collected and used to map the progression of the change in space and time. The social background of document signatories is also used to map the progression of the change through different social groups. A variety of different patterns emerge for the different changes examined. Some changes spread by contagious diffusion, but many spread by hierarchical diffusion, jumping first between cities before spreading to the country at large. One common theme which runs through much of the findings is that dialect contact within the North Germanic language area seems to have played a major role: many of the different simplificatory changes may first have spread into Norwegian from Swedish or Danish. Although these findings do not exactly match the simple predictions originally proposed from the sociolinguistic typological theory, they are potentially consistent with a more nuanced account in which the major centres of contact and so simplifying change were in Sweden and Denmark rather than Norway.