o Overview
-> Causes of trade growth
-> Maritime technologies
-> Economic and political effects
o Causes of trade growth
-> After 1200, older Indian Ocean routes grew in volume.
-> Rising demand for spices and textiles drew merchants.
-> Chinese production supplied porcelain and silk exports.
-> Muslim merchant networks linked distant port markets.
-> Shared commercial ties eased credit and negotiation.
-> Port rulers protected commerce to gain customs revenue.
o Maritime technologies
-> Lateen sails helped ships tack against the wind.
-> Chinese junks used sternpost rudders for steering.
-> Magnetic compasses improved navigation offshore.
-> Mariners shared shipbuilding and navigational knowledge.
-> Larger ships moved bulk cargo more cheaply than caravans.
o Economic and political effects
-> Sea routes linked East Africa, Arabia, India, and China.
-> India exported cotton cloth; Southeast Asia sent spices.
-> Swahili ports exported gold and ivory from the interior.
-> Trade wealth expanded cities such as Kilwa and Calicut.
-> Malacca's strait location enriched its trading sultanate.
-> Zheng He's voyages (1405-1433) extended Ming diplomacy.
o Overview
-> Monsoons and maritime geography
-> Merchant diasporas
-> Cultural and environmental exchange
o Monsoons and maritime geography
-> In c. 1200-1450, seasonal winds structured ocean trade.
-> Summer monsoons aided voyages from Arabia toward India.
-> Winter wind reversals helped ships make return voyages.
-> Predictable winds let sailors schedule long crossings.
-> Waiting for wind changes prolonged merchants' port stays.
-> Natural harbors and narrow straits concentrated traffic.
o Merchant diasporas
-> Seasonal stays fostered foreign merchant communities.
-> Arab and Persian merchants settled in East African ports.
-> Muslim traders also formed communities in Indian ports.
-> Diaspora ties supplied contacts, credit, and market news.
-> Intermarriage linked foreign merchants to local families.
o Cultural and environmental exchange
-> Merchant contacts spread Islam without universal conquest.
-> Some Southeast Asian rulers adopted Islam and trade ties.
-> Swahili blended Bantu roots with Arabic loanwords.
-> Coastal Islamic practices coexisted with local traditions.
-> Sea trade moved crops, including citrus, into new regions.
-> Connected ports also enabled infectious disease to spread.