In the Middle Ages, war and commerce were closely linked. Every year, an enormous quantity of valuable merchandise: pepper, spices, iron tools, grain, glass, copper ingots, textiles, furs, fish, wine, and beer, flowed down the sea-lanes from one port to another, driving much of the economic activity of the era.
Trade was conducted across thousands of miles, through barriers of language and religion, and in spite of capricious weather and daunting logistical challenges. Goods and people travelled from the shores of England, across the breadth of Europe, via trade routes like the Silk Road, over the Central Asian steppe, and as far as Persia, India, and China. Commerce drove prosperity, which was the glue that held commercial relations together. But when trust eroded, commerce suddenly gave way to war.
Trade…
