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World History Unit 2: Networks of exchange (c. 1200–1450)

Trade networks and the Mongol Empire linked Afro-Eurasia, spreading goods, ideas, technologies and disease.

Covers: The Silk Roads, the Mongol Empire, Indian Ocean trade, trans-Saharan trade, cultural consequences, environmental consequences

Study guide

The Silk Roads connected China, Central Asia, the Middle East and Europe by land. Luxury goods like silk and porcelain moved long distances, supported by caravanserai (roadside inns), the camel saddle, bills of exchange and paper money. Trading cities like Kashgar and Samarkand grew rich. The Mongol Empire, founded by Chinggis (Genghis) Khan, became the largest contiguous land empire in history. The Mongols conquered China (founding the Yuan dynasty under Kublai Khan), Persia, Russia and Central Asia, then protected trade across their lands. This Pax Mongolica let merchants and travelers like Marco Polo move safely, and it spread technologies like gunpowder and printing westward.

The Indian Ocean was the largest sea-based trade network. Monsoon winds blew predictably in different directions by season, so sailors could plan voyages. Ships like the dhow and Chinese junk, the magnetic compass and the astrolabe made sea travel easier. Port cities like Calicut, Malacca and the Swahili city-states (Kilwa, Mombasa) thrived, and diasporic communities of merchants settled in foreign ports, spreading their cultures. The Ming admiral Zheng He led huge treasure fleets across the Indian Ocean in the early 1400s to display Chinese power and collect tribute. Across the Sahara, camel caravans carried gold from West Africa and salt from the desert, enriching Mali and spreading Islam.

These exchanges had big cultural effects. Buddhism, Islam and Christianity spread along trade routes, and travelers like Ibn Battuta wrote about the societies they visited. Technologies and crops moved too, such as Champa rice to China and sugar and citrus around the Mediterranean. Trade also spread disease: the Black Death (bubonic plague) traveled along the Silk Roads in the 1340s and killed a third or more of Europe's population, causing labor shortages and social upheaval.

Chinggis Khan united the Mongol clans by 1206 and promoted commanders for loyalty and skill rather than birth. His armies combined expert horse archers with siege engineers borrowed from conquered peoples. The Mongols ran a relay system of postal stations (the yam), took censuses, tolerated many religions and employed Persian, Chinese and Muslim officials. After disputes over succession, the empire split into khanates: the Yuan in China, the Ilkhanate in Persia, the Chagatai in Central Asia and the Golden Horde in Russia. The Ilkhans converted to Islam and adopted Persian culture. The Golden Horde collected tribute through Russian princes, which helped Moscow rise. In China, the Yuan ranked Mongols above Chinese and restricted the civil-service exams until the Ming overthrew them in 1368.

Swahili culture blended Bantu African and Arab-Persian influences, seen in the Swahili language and the coastal mosques, and merchants rather than conquerors spread Islam there. In West Africa, Timbuktu became a major center of trade and Islamic scholarship. Overland trade favored high-value, lightweight luxuries. Sea routes could carry bulkier goods like textiles, spices and ceramics more cheaply, so ports thrived even when land routes were disrupted.

Key ideas

• The Silk Roads carried luxury goods across Eurasia by land.
• The Mongols built the largest land empire and protected Eurasian trade.
• Monsoon winds made the Indian Ocean the largest trade network.
• Trade spread religions, technologies, crops and disease.
• The Black Death moved along trade routes and devastated Afro-Eurasia.

Formulas and rules

Common mistakes

• Thinking the Mongols only destroyed; they also protected trade and spread ideas.
• Confusing Zheng He's voyages with European exploration; they displayed power rather than starting colonies.

Words to know

Silk Roads

Overland trade routes linking China and the Mediterranean.

Caravanserai

Roadside inns for merchants on the Silk Roads.

Bills of exchange

Paper documents used like checks for long-distance trade.

Chinggis Khan

Founder of the Mongol Empire.

Yuan dynasty

Mongol-ruled dynasty in China founded by Kublai Khan.

Pax Mongolica

Period of peace and safe trade across Mongol lands.

Monsoon winds

Seasonal winds that made Indian Ocean voyages predictable.

Dhow

Arab sailing ship used in the Indian Ocean.

Swahili city-states

East African trading cities like Kilwa and Mombasa.

Diasporic community

Merchants living in a foreign port who keep their own culture.

Zheng He

Ming admiral who led treasure fleets across the Indian Ocean.

Ibn Battuta

Muslim traveler who wrote about Afro-Eurasian societies.

Marco Polo

Venetian merchant who described the Mongol court in China.

Trans-Saharan trade

Camel caravan trade of gold and salt across the Sahara.

Black Death

Bubonic plague pandemic that spread along trade routes in the 1340s.

Sample practice questions

5 more questions like these, from level 1 to 5, are in the practice set.