Economic historians have placed commercialization at the centre of Europe’s early modern capitalism, emphasizing the importance of domestic and international trade, shipbuilding and concomitant manufactures, the financial sector, and urbanization. As the Iberian polities extended geographically to Africa, Asia and the Americas during the early modern period, trade, whether domestic, international or colonial, had a critical effect upon economic development. However, the economic impact of colonial expansion was uneven across Iberia. Iberia commercial exchange associated with the overseas empires produced surprisingly few backward and forward linkages in the European national economies. The question this chapter seeks to address is thus to what extent and how Iberian trade, especially colonial trade, supported or hindered economic development in the early modern period.