One of the popular routes/roads of trade that emerged was called “the silk
road", which gained notoriety some 2,000 years ago, as it was specifically
created for trading all sorts of stuff: animals, clothes, textiles, wood,
vegetables, metals, etc. The route earned its name because ‘silk’ was a
primary material that the Chinese used to create clothes, and it was a very
useful material at that time. The Chinese discovered how to make ‘silk’
textiles some 5,000 years ago by ‘milking’ insects, but silk did not expand
into global trade for another 3,000 years or so. The “Great Wall of China"
was built as a protection measure for the growing ‘silk road’ trade ‘system’.
But there was a problem with using ‘currency’ for trading in this period of
time: insecurity. It is one thing to use a currency within a single tribe, but it’s
a different story when you try to use it globally.