Beginning in the 1160s, the opening of new silver mines in northern Europe led to the minting and circulation of vast quantities of silver coins. The widespread use of cash greatly increased the volume of international trade.Business procedures changed radically. The individual traveling merchant who alone handled virtually all aspects of exchange evolved into an operation involving three separate types of merchants: the sedentary merchant who ran the "home office," financing and organizing the firm's entire export-import trade; the carriers who transported goods by land and sea; and the company agents resident in cities abroad who, on the advice of the home office, looked after sales and procurements.
Commercial correspondence, unnecessary when one businessperson oversaw everything and made direct bargains with buyers and sellers, multiplied. Regular courier service among commercial cities began. Commercial accounting became more complex when firms had to deal with shareholders, manufacturers, customers, branch offices, employees, and competing firms. Tolls on roads became high enough to finance what has been called a road revolution, involving new surfaces and bridges, new passes through the Alps, and new inns and hospices for travelers. The growth of mutual trust among merchants facilitated the growth of sales on credit and led to new developments in finance, such as the bill of exchange, a device that made the long, slow, and very dangerous shipment of coins unnecessary.
The ventures of the German Hanseatic League illustrate these advancements. The Hanseatic League was a mercantile association of European towns dating from 1159. The league grew by the end of the fourteenth century to include about 200 cities from Holland to Poland. Across regular, well-defined trade routes along the Baltic and North seas, the ships of league cities carried furs, wax, copper, fish, grain, timber, and wine. These goods were exchanged for finished products, mainly cloth and salt, from western cities. At cities such as Bruges and London, Hanseatic merchants secured special trading concessions, exempting them from all tolls and allowing them to trade at local fairs. Hanseatic merchants established foreign trading centers, the most famous of which was the London Steelyard, a walled community with warehouses, offices, a church, and residential quarters for company representatives. By the late thirteenth century, Hanseatic merchants had developed an important business technique, the business register. Merchants publicly recorded their debts and contracts and received a league guarantee for them. This device proved a decisive factor in the later development of credit and commerce in northern Europe.
These developments added up to what one modern scholar has called "a commercial revolution." In the long run, the commercial revolution of the High Middle Ages (A.D.1000–1300) brought about radical change in European society. One remarkable aspect of this change was that the commercial classes constituted a small part of the total population-never more than 10 percent.They exercised an influence far in excess of their numbers. The commercial revolution created a great deal of new wealth, which meant a higher standard of living. The existence of wealth did not escape the attention of kings and other rulers. Wealth could be taxed, and through taxation, kings could create strong and centralized states. In the years to come, alliances with the middle classes were to enable kings to weaken aristocratic interests and build the states that came to be called modern.
The commercial revolution also provided the opportunity for thousands of agricultural workers to improve their social position. The slow but steady transformation of European society from almost completely rural and isolated to relatively more urban constituted the greatest effect of the commercial revolution that began in the eleventh century. Even so, merchants and business people did not run medieval communities, except in central and northern Italy and in the county of Flanders. Most towns remained small. The nobility and churchmen determined the predominant social attitudes, values, and patterns of thought and behavior. The commercial changes of the eleventh through fourteenth centuries did, however, lay the economic foundation for the development of urban life and culture.