The present-day border between Belgium and the Netherlands traces back to the separation of the Low Countries after the Dutch Revolt (1566-1648) against Spanish rule. The capacity to finance the escalating costs of war determined the outcome of this conflict. As Spain struggled to provide regular pay to its troops, its war efforts were often plagued by mutiny. By contrast, the Dutch Republic managed to raise large sums for its war budgets. As we show in this paper, excise taxes on beer consumption were one of the largest income sources in Holland, the leading province of the Dutch Republic. Over the course of the Revolt, Dutch beer taxes brought in the equivalent of 29% of Spanish tax revenues on silver from America. Beer taxes thus played a crucial role in financing the Dutch Revolt which led to the separation of the Low Countries and, eventually, the creation of Belgium.