the "old market"; presumably only Christians could get access to what was new.
One can imagine the confusion resulting having double the number of people show up to strain regulatory plans: "Europe's population grew steadily in the Central Middle Ages" (Hollister and Bennett 156). Undoubtedly lodging, rule enforcement (for example of "Troy" weight on the scales), and "security" were problematic. The Champagne fairs became a gathering venue for merchants from many different places (Gies and Gies 108). The trade-fair concept was duplicated in key transportation outlets. The northern German cities of the Hanseatic League--Cologne, Hamburg, and Bremen--became the earliest beneficiaries of enlarged trade because of their status as ocean and river ports. The merchants were engaging in sea trade, which kept the flow of goods alive. Organizing into guilds (Gies and Gies 124), they were also getting more social privileges, as Henry II's document reciting the financial and social privileges of Newcastle's burgesses makes clear (Customs 174-5). By the 12th century, skilled-trade guilds (carpenters, brewers, metalsmiths, etc.) were also being organized and were responsible for many technological inventions to facilitate their work.
By the 13th century the Italians had mastered double-entry bookkeeping as the core record-keeping device of commerce, which spread gradually to northern Europe. Italy led the way in rationalizing monetary exchange and banking on an international scale (Gies and Gies 184-5). Financial diversity--despite some horrific bankruptcies stemming from speculation--seems to have been a key impetus to formation of Italian city-states. Financial savvy would help explain why Milan, Venice, Florence, and Genoa had populations more than 100,000 by 1300 (Hollister and Bennett 156).
Also in the 12th century there was a pre-Renaissance revival of education and rediscovery of Greek and Roman classic texts. Cathedral schools were ...