How Britain Unified Germany: Trade Routes and the Formation of the Zollverein

Does the location of a state relative to others matter? We argue that a state’s location can affect its bargaining power, and thereby multilateral relations, if trade costs depend on trade routes that pass through other states. This is an important, yet neglected aspect of economic history. We show how an exogenous border change - caused by Britain’s intervention at Vienna in 1815—affected the location and trade routes of Prussia and other German states. We find that this border change led to the formation of the first customs union in history, the German Zollverein of 1834.