The Iberian Peninsula in the fifteenth and sixteenth centuries was the leader of European expansion on a global scale. The Portuguese initiated European world domination through the conquest of the oceanic trade routes of Africa and Asia. And Spain – and more specifically the Castillian kingdom within the Spanish state – undertook the conquest and settlement of vast territories of the Western hemisphere. America, unlike Africa and Asia, was unknown and unintegrated into the Eurasian world prior to the fifteenth century. By its American conquest, Spain provided a whole new arena for exclusive European settlement and development that in turn gave Europe a decided advantage in its race for world influence. Thus, the Castillian conquest of the lands of America, along with the Portuguese conquest of the international sea lanes, finally tipped the balance of world economic power to Europe and helped prepare the way for its ultimate industrial domination as well. The conquest of America in the late fifteenth and early sixteenth century was thus crucial in changing the relative importance of Europe in the world, and in defining a new world historical era.