Colonialism began with the era of European exploration; in 1493 a Line of Demarcation assigned to Spain and Portugal spheres of influence in the Western Hemisphere and West Africa. France, England, and other countries soon vied for territory in North America. The zenith of colonialism came in the late nineteenth and early twentieth centuries, when most of Africa and Asia were under European economic or political control. Renewed evangelism in Africa took place at this time, in large part through the efforts of mission societies. The aims of missionaries often placed them in conflict with colonialists who sought only profit and political control. To be sure, some missionaries believed that it was their duty to bring western civilization to the world, yet many others learned and preserved tribal languages, translated scriptures, and adapted their way of life to their surroundings. Training local Christians who could shape and lead their own communities was a high priority for many missionaries. Colonialism began to weaken after World War I and was rapidly dismantled after World War II.