From 1200 to 1450, major societies across the world developed distinctive political systems while still sharing common patterns of state-building. In Song China, rulers relied on , the imperial bureaucracy, and the to justify order, while innovations like , expansion of the Grand Canal, and growing commercialization strengthened the economy. In Dar al-Islam, the decline of the led to new states like the Mamluk Sultanate and Delhi Sultanates, while Islam spread through conquest, trade, and the work of . In South and Southeast Asia, Hinduism, Buddhism, and Islam shaped states such as the Khmer Empire, Majapahit, and Srivijaya, while religious movements like Bhakti influenced daily life and monumental architecture such as . In the Americas, the Mexica and Inca built powerful empires using systems like tribute and the . In Africa, states such as , Ethiopia, and Great Zimbabwe expanded through trade and regional power. Meanwhile, Europe remained politically fragmented under , the , and decentralized monarchies, while Christianity, along with Judaism and Islam, continued to shape European society.

Between 1200 and 1450, expanding trade networks connected Afro-Eurasia more deeply than ever before. The , , and trans-Saharan trade routes all grew because of improved transportation, commercial practices, and rising demand for luxury goods. Along the Silk Roads, technologies such as , , and systems of credit supported exchange, while goods like textiles, porcelain, and steel moved across continents. The rise of the intensified these connections by making travel and trade safer and encouraging cultural and technological diffusion. In the Indian Ocean, sailors used , the compass, the , and improved ships to connect cities from East Africa to Southeast Asia, supporting states like and the Swahili Coast city-states. Travelers such as and Marco Polo recorded these interconnections, while the spread of bananas, new rice strains, and the showed that exchange had environmental as well as cultural effects.

From 1450 to 1750, large land-based empires expanded through military power, especially the use of , cannons, and professional armies. Major empires included the , the , the , and the . These states built powerful centralized governments by recruiting military elites and loyal administrators, such as the Ottoman system and peasant warriors like the . Systems such as and zamindar tax collection helped these empires raise revenue and sustain expansion. The challenged the Catholic Church and transformed Christianity, while rivalry between the Sunni Ottomans and Shi'a Safavids deepened divisions within Islam. In South Asia, emerged from interactions between Hinduism and Islam.

Between 1450 and 1750, oceanic travel connected the Eastern and Western Hemispheres in new ways and created a truly global system. European exploration was made possible by technologies including the , compass, astrolabe, , and fluyt. Portugal built a trading-post empire in Africa and Asia, while Spain sponsored Columbus to conquer large American empires. These voyages sparked the , which transferred crops, animals, people, and diseases between hemispheres. American crops like and potatoes boosted populations in Afro-Eurasia, while Europeans brought horses, cattle, sugar, and devastating diseases such as , measles, and malaria to the Americas. European maritime empires established colonies and plantation economies that relied on systems like , hacienda, indentured servitude, and . and helped states maintain overseas empires, while the global flow of , especially from Spanish America to China, tied world markets together.

From 1750 to 1900, revolutions in politics, thought, and industry transformed societies around the world. The promoted reason, , and the , encouraging people to challenge monarchy, tradition, and inherited privilege. Thinkers inspired revolutionary movements such as the American Revolution, French Revolution, , and Latin American independence movements. At the same time, united people around shared language, culture, and territory, contributing to new nation-states and unifications such as Germany and Italy. Meanwhile, the began in England, fueled by coal, iron, waterways, urbanization, capital, and agricultural improvements. The factory system concentrated labor and increased productivity, while machines like the and later the internal combustion engine transformed manufacturing and transportation. New economic ideas emerged, including laissez-faire capitalism, free trade, , and , while industrial society gave rise to labor unions, urban reform, and critiques by thinkers like .

As industrialization accelerated, powerful states sought raw materials, labor, and markets through a new wave of imperialism. European empires, along with the United States and Japan, justified expansion with ideologies such as , nationalism, the , and missionary Christianity. In some cases, colonial control shifted from private hands to governments, as seen in the under and later Belgium. Economic imperialism also gave industrialized nations major influence without full political control, as seen in the in China. These pressures sparked resistance, including the , the rise of the , and the . Industrialization also drove global migration, while systems of moved Chinese and Indian laborers worldwide. Migrants formed ethnic enclaves but also faced racism and exclusion, such as the and the White Australia policy.

The 20th century was defined by dramatic shifts in power, revolution, and catastrophic warfare. World War I erupted because of , alliances, imperialism, and nationalism, becoming the first major , in which governments used , mass mobilization, and industrial weaponry to fight on an unprecedented scale. After the war, the led governments to intervene more actively in economic life through programs like the , fascist corporatism, and in the Soviet Union. Unresolved tensions, punitive treaties, economic collapse, and aggressive fascist regimes led to , another total war marked by fire-bombing, the , genocide, and even greater destruction. The , in which Nazi Germany attempted the extermination of Europe's Jews, stands as the most infamous mass atrocity of the era, alongside the and other campaigns of ethnic violence.

After World War II, the world entered a new era shaped by and the . European empires weakened, and anti-imperialist movements grew stronger, leading colonies in Asia, Africa, and the Middle East to seek independence. Some gained freedom through negotiation, as in India and Ghana, while others fought wars of liberation, as in Algeria and Vietnam. At the same time, the global balance of power shifted to the United States and the Soviet Union, whose ideological rivalry between capitalism and communism defined the Cold War. This struggle produced alliances such as and the , as well as in places like Angola, Nicaragua, and Vietnam. Some nations tried to avoid choosing sides through the , led by figures like and . Individuals such as , Martin Luther King Jr., and challenged power through nonviolence.

Since 1900, and especially since the late 20th century, the world has become increasingly interconnected through . New technologies such as radio, cellular communication, the internet, air travel, and reduced geographic distance and accelerated the movement of ideas, goods, and people. Advances in petroleum, nuclear power, vaccines, antibiotics, and birth control transformed standards of living, while the increased food production and helped sustain a growing global population. At the same time, globalization intensified environmental challenges, including debates over caused by . Economically, many governments embraced , from Margaret Thatcher in Britain to Deng Xiaoping in China. Multinational corporations, trade agreements like , and institutions such as the reflected this new global order. Yet globalization also sparked resistance and encouraged reform movements including the , global feminism, and the .