The third of the series on things that changed the world from Livescience, this time - the economic benefits of trade. As urbanization began to take root, people began to specialize in particular skills and learned to trade the items they produced with other people for the items they mnaufactured. Then cities themselves began to get into the act.
"When people first settled down into larger towns in Mesopotamia and Egypt, self-sufficiency – the idea that you had to produce absolutely everything that you wanted or needed – started to fade. A farmer could now trade grain for meat, or milk for a pot, at the local market, which was seldom too far away.
Cities started to work the same way, realizing that they could acquire goods they didn't have at hand from other cities far away, where the climate and natural resources produced different things. This longer-distance trade was slow and often dangerous, but was lucrative for the middlemen willing to make the journey."
While the earliest trade networks go far back into pre-history, these were relatively small scale, short term affairs. Extensive long term organized trade goes back to around 3000 BC, when the Mesopotamian civilizations of the Near East began to exchange items with the Indus Harrapan civilization of found in modern day Pakistan.
The dangers involved in such long distancre trading required a high pay off, so the majority of trade items were luxury goods such as spices, jewelry and the like. Both the indivduals and the cities involved in such trade (whether found nearby or located on the routes travelled by merchants) exchanging such goods could become fantastically wealthy. Specialized resources located in very specific areas such as copper, tin, silk, cedar wood, purple dyes, jade, spices and papyrus could be exchanged over thousands of miles.
The easiest and probably most secure method of transporting large amounts of such goods was by water, with early river civilzations in Mesopotamia, Egypt and China benefitting from their fertile agricultural river valleys and then using the riverways to transport goods regionally. Later developments allowed naval sea powers located in the Mediterranean such as Cyprus, Crete, Phoenicia, Carthage, Greece and eventually Rome to reap enormous benefits from their control of the sea lanes. The domestication of the camel around 1000 BC allowed the first extensive long term land routes to be established across the forbidding terrain of North Africa and Central Asia.