Nationalism is loyalty to one's nation rather than to an individual leader. It arose in the Middle Ages and was strengthened by the Industrial Revolution as new nations formed and organized sports grew in popularity. Governments created nationalism by developing national anthems, writing standardized history books, publishing folk stories, establishing mandatory public schools, standardizing languages, building strong militaries, starting wars, and using propaganda. Both positive and negative impacts can result from nationalism. Imperialism involves the domination of one nation over others, motivated by nationalism, racism, capitalism, and a sense of adventure.