Tying a hemisphere together

• Marco Polo (1271-1295)
• Ibn Battuta (1304-1369)

Zheng He (expeditions: 1405-1433)

• A Chinese discovery of America?
• The end of the Ming voyages

Christopher Columbus (expeditions: 1492-1502)

• The discovery of America?
• Opening the world's oceans

Roads (and sea lanes) to global interactions