Hilary Green takes the reader on a journey through the complex developing trade of the Middle Ages, which is the foundation of trade today. Taking the production of wool in the abbeys of the north of England as a starting point, she follows its journey to Flanders where it was woven into a variety of textiles in the growing international marketplace of Bruges. The journey continues to Bordeaux where the wool was traded for wine, which found its way back to London where some of it was traded for more wool. She describes the trade fairs of the Champagne region of France where wool and leather goods along with salt, iron and other commodities were traded and where banking developed - and she explains why.

The merchants of Genoa developed the various trade routes, whether by land over the Alps or by water via rivers or the Mediterranean. By these routes, silks and spices came from the repositories in Alexandria and before that via camel trains from Arabia.

The author investigates the mysteries and intrigue of trade where silkworms were smuggled into Constantinople and precious gems and ivory were shipped from unknown locations. Arab and Indian merchants brought exotic spices - cumin, ginger, pepper, nutmeg and cinnamon - and aromatics such a myrrh and frankincense to Egypt via the Red Sea. As trade expanded and became more valuable, international relations became more sophisticated as governments moved to protect the valuable income it brought.