Cohesive exchange relations (gold nodes) supported the creation of wealth among merchants and merchant cities, with states supported by indirect taxation and loans. Northern Europe is not well represented here (and locations are not geographic), but the main Hanseatic League port of Lubeck had about 1/6th the trade of Genoa, 1/5th that of Venice. Unclick all but the principal banking routes to see how centralized is the spine of the exchange system, linking four parts through Alessandria was a small stronghold fortification built (1164-67) by the Lombard League and named for Pope Alexander III. At first a free commune, the city passed in 1348 to the duchy of Milan.
Ancillary Courier Routes for Banking
Principal Courier Routes for Banking
Venetian Fleet Routes
addl Genoan Fleet Routes
Next - Competition over Wool/Woolens Trade

Map of Trade Links