For more than a fifteen centuries goods and ideas traveled the mostly overland trades routes from East Asia, the subcontinent, and the Middle East to the lands of the Mediterranean. These routes are most often referred to as the "Silk Road" as this was the single most valuable commodity carried by the merchant traders.
Travel along these routes was dangerous and expensive. Every Empire, kingdom and city state along the Silk Road took their fair share of the profits through taxes, service charges and the like. From the cities of China to the great Eastern Roman city of Constantinople the goods flowed and money flowed with them. The massive wealth gained from this trade was a major reason for the long life of the Eastern Roman Empire.
But silk was not the only commodity carried, spices, gems, rare animals, slaves and numerous other valuable items traveled the route.
Gold flowed freely from West to East in a steady stream of negative trade balance from the coffers of the Europeans for the goods they treasured but could not produce.
An even more important item traveled with the merchants and their caravans-ideas. Religions, inventions, such as paper(this is an ancient Chinese paper discussing Buddhism)stories, cultural concepts, all traveled along the Silk Road helping to spread the knowledge of mankind throughout three continents.
The Ottoman conquest of the Eastern Roman Empire did not end this trade, they simply increased the "carrying charges." The increased expense, and the possibility of cutting out the "Middle Man" lead several European kingdoms to look for alternate, cheaper trade routes. So in 1492, a little known Italian, sailing with three small Spanish ships set out for the riches of Asia and discovered a new world unknown to the peoples of the East and the history of mankind was forever changed.