The Salt Roads

[A] For most of history salt was not a seasoning but a technology. Without it, meat and fish could be kept for a few days in a warm climate and no longer, so the ability to preserve a summer catch through a winter decided whether a settlement could grow. [B] This made salt worth carrying enormous distances.

The trade across the Sahara is the clearest case. [C] Slabs of rock salt were cut at desert mines, loaded onto camels and taken south to the cities of the Niger, where salt was scarce and gold was not. The exchange is often described as salt for gold weight for weight, which is almost certainly an exaggeration by later European writers, but the ratio was startling enough without it. [D] What deserves more attention than the romance of the caravans is who profited. The mines and the markets lay in different kingdoms, and the wealth accumulated in neither: it went to the states in the middle, which controlled the wells. Whoever owns the water on a desert route owns the route, and the empires that grew rich on this trade never mined an ounce of salt or panned a grain of gold.