Belgium was one of the first continental countries to undergo the industrialization process during the 19th century. Along with the growing manufacturing base came the development of an extensive transportation infrastructure. As a result, the Belgian internal market became fully integrated towards the beginning of the 20th century, making the country a perfect case study to examine the driving forces behind the shifting industrial pattern and location decisions of industries. More specifically, it allows us to test the theoretical predictions of the Heckscher-Ohlin model, which emphasizes the importance of proximity to factors of productivity, relative to those of the New Economic Geography, which stresses closeness to industrial agglomerations and consumer markets. In this article, we use a model that nests factors of both theories. The empirical analysis of the nuts-3 data indicates that the main determinant of the shifting industrial pattern between 1896 and 1961 -- with the south being superseded by the north as the economic powerhouse -- was the closeness to regions with a high market potential.