Three Networks and What Moved on Them

The Silk Roads

Overland routes across Central Asia carried light, high-value goods — silk, porcelain, spices — because transport cost per unit weight was high. Enabling technologies: the camel saddle, and caravanserai (roadside inns) that made long journeys survivable and gave merchants places to exchange credit and information.

What else moved: Buddhism into East Asia, printing and paper technology westward, and eventually the Black Death.

The Indian Ocean

The decisive advantage of sea transport is volume. Ships could carry bulk goods — timber, grain, textiles in quantity — that would never repay overland carriage.

Enabling technologies: knowledge of monsoon winds, the dhow, the lateen sail allowing sailing closer to the wind, the compass and the astrolabe.

Because merchants had to wait months for the winds to reverse, they settled — producing diasporic communities in port cities, and the Swahili language and culture along the East African coast, blending Bantu with Arabic.

Trans-Saharan routes

Camels and oasis chains linked West Africa to the Mediterranean. Gold moved north, salt moved south — salt being essential and scarce in the interior. This trade financed Mali and later Songhai, and carried Islam into West Africa, making Timbuktu a centre of scholarship.