The nineteenth century was a period in which nation states with considerable success created strict borders for their countries, thus separating people in border regions who had thus far lived together, speaking the same dialect and often adhering to the same type of religion. National languages were to replace regional dialects, and material signs such as customs offices stressed the borders.

This was supported by the rise of nationalism. Intellectuals and politicians constructed national identities in order to strengthen the inner cohesion of the state they envisaged, while at the same time drawing clear borders with those who were considered not to be part of the nation. Nationalism strived for a unified nation, with a minimum of internal borders, which meant for Jews that they had either to integrate into the nation or were considered foreigners who had no real attachment to the national space. As a consequence, the external borders were made particularly strong – which resulted in suspicion of subgroups in society with important transnational networks, such as Jews and Catholics. Against this background, borders might be defined as attempts to define and fix what belongs or does not belong in a given space.

Nineteenth-century nationalism challenged Jews in particular, since they were expected to show loyalty and patriotism after acquiring emancipation or in the process of acquiring it. Jews in border regions that changed from one nation to another due to wars were especially confronted with these themes. In this context, they had a variety of options, maybe even more than others. They could choose to remain loyal to the former nation or to take sides with the new authorities. But they also had a third possibility, namely to supersede both national positions by articulating a Jewish national identity. In this article, I concentrate on one such case, namely the attitude of the Jews towards the formation of the Belgian nation state after it split off from the United Kingdom of the Netherlands. It was the first territorial change in Europe after the Congress of Vienna, which makes it an interesting case for analyzing what factors determined in this early stage of the nineteenth century the positions Jews chose in reaction to politically motivated spatial changes.