Charles V sought to become leader of universal empire. His imperial dreams were encouraged by M.A. Gattinara. The chief problems Charles V faced were the Protestant Reformation in Germany, provided by Martin Luther. In the era of exploration, discovery, and colonization, Spain amassed tremendous wealth and a vast colonial empire through the conquest of Mexico by Cortés (1519-1521) and Peru by Pizarro (1532-1533). The Spanish Hapsburg monarchy became for a time the most powerful in the world.