The enduring Roman idea that establishing saltworks was synonymous with building empires was carried forward into the maritime republics that rose after Rome’s collapse in the fifth century. The Mediterranean, once the most economically vital region of the Western world, entered a period of intense competition.
Venice, founded in the swampy region near Ravenna, quickly rose to prominence. Settled in the Adriatic lagoons, the early Venetians focused their entire emulation on the saltworks, as Cassiodorus recorded in 523 A.D..
He stated that their industry made all other products dependent upon them, because “there never yet lived the man who does not desire salt, which makes every food more savory”.
The location of the city was not driven by the immediate proximity of vast salt beds, but by the pivotal river system at its back. The Po River flows across the peninsula, spreading into a marshy estuary from Ravenna to Venice. The valley of the Po—today known as Emilia-Romagna—is Italy’s most affluent agricultural region. The wealth of this region required two things: a port for its goods and a reliable source of salt for its farming and food preservation. Venice competed fiercely with Genoa, located on the Mediterranean side of the Po, for this critical commercial business.
The Technological Leap of the Lagoons
Between the sixth and ninth centuries, salt manufacturing saw its last great technical advance until the twentieth century. Instead of trapping seawater in a single artificial pond, salt makers began constructing a series of successive evaporation ponds. This systematic process required minimal investment and equipment, except for the final harvesting stage.
The sequence starts with a large open tank where seawater is held. Pumps and sluices move the water to the next pond after it reaches a heightened salinity. This process is repeated, with the water evaporating further in each successive pond, yielding an increasingly dense brine. When the brine reaches sufficient density, the salt precipitates out, crystallizing and sinking to the bottom where it can be scooped up. In a single pond relying only on solar heat, this might take a year or more. But this successive system, given sufficient sun, wind, and dry weather, is limited only by the surface area available for the ponds.
The coarse salt produced by this slower evaporation method was highly valued in the Mediterranean for curing hams and salting fish. North African Muslims, operating in the early Middle Ages, may have been the first to use such a system, introducing it to Ibiza in the ninth century. Venice quickly exploited this superior technology.
The Monopoly Machine
No state, save China, had based its economy on salt to the degree Venice had. The city secured a full monopoly on salt sales and transportation along its extensive trade routes.
The pillars of Venice’s state salt policy were rigid and coercive:
- Prohibition of Rivals: Starting around 850 A.D., Venice prohibited the import of salt from rival saltworks.
- Forced Purchase: The city forced territories under its control to purchase all their salt exclusively from Venetian merchants. By 1300, Venice even compelled Crete and Cyprus to stop their own salt production and rely entirely on Venetian supply.
- Price Control: Venice bought salt cheaply from remote coastal operations, such as those in Crimea, and then sold it at a fixed, high profit margin. The government even enforced a minimum price below which its citizens were forbidden to sell salt.
Venice’s extensive salt administration, which generated great wealth and power, may have been influenced by its best-known family, the Polos. Niccolò Polo and his brother Maffeo, Venetian merchants, traveled to the court of Kublai Khan in 1260. Though the Dominicans who initially accompanied them abandoned the arduous trek, Marco Polo, Niccolò’s seventeen-year-old son, stayed on and served the Khan.
The Salt in the Prosciutto
The competition for the affluent Po Valley market fueled the rivalry between Venice and Genoa. The Po Valley relies on a port for its goods and a source of salt for its agriculture.
The Romans had built the Via Emilia—now the eight-lane A-1 superhighway—connecting major cultural and commercial centers from Piacenza to Parma to Bologna and on to the Adriatic coast.
The area contained highly valuable salt resources, particularly the brine wells located inland, near Veleia (later Salsomaggiore, “the big salt place”). The earliest records of salt production in Veleia date from the second century B.C.. Charlemagne restarted Veleia’s saltworks after the fall of the Roman Empire to supply his army. These ancient brine wells utilized massive wooden wheels, sometimes powered by men chained at the neck, to hoist buckets of brine. Because boiling this brine required immense quantities of wood, controlling the wells necessitated controlling the wide surrounding forest area.
The struggle over these resources was constant. In 1318, the city of Parma seized control of thirty-one wells from the feudal Pallovicino family, an event recorded in a fresco in the city palace.
This marked the transfer of power from the feudal lord to the city government.
Parma became renowned for its most famous salt product, prosciutto di Parma. The location proved ideal because the mountain peaks trapped the sea air, drying the wind needed for aging the salted leg without rotting. The drying racks for the hams were specifically arranged east to west to optimize exposure to this dry wind. The quality of the ham was also credited to the local diet of the pigs: the Po Valley is Italy’s only major dairy region, and the whey leftover from making Parmigiano-Reggiano cheese was fed to the pigs. This cheese, cured in brine, requires two years for the salt to reach the center of a ninety-pound wheel. The Latin word for a wooden cheese mold, forma, is the root of the Italian word for cheese, formaggio. The whey-fed pigs were considered a requirement for prosciutto di Parma.
The Fall of Genoa and the Atlantic Pivot
Genoa, an independent city-state dedicated to commerce by the twelfth century, was Venice’s major Mediterranean competitor. Genoa sourced salt from several sites, enhancing production at Hyères (Provence) by building solar evaporation ponds and developing the saltworks of Cagliari in Sardinia. They also purchased salt from Tortosa, located at the mouth of the Ebro River.
In Spanish Catalonia, the Dukedom of Cardona controlled a famous salt mountain, a source of salmon pink, white, and bloodred rock salt that had been harvested since at least 3500 B.C.. Prehistoric stone tools used for scraping salt have been found there. Though the Romans usually favored sea salt, they considered Cardona’s rock salt to be high quality. Salt workers in Cardona were allowed to take salt for themselves every Thursday and used the soft, soluble rock salt to carve religious figurines.
Genoa pioneered maritime insurance and banking, using huge Atlantic-sized ships, often leased from the Basques, which had ample cargo space for salt on return voyages. However, Venice eventually secured commercial dominance through its superior political organization and salt subsidies.
The competition culminated in the War of Chioggia (1378–1380), where Venice defeated Genoa decisively by converting its commercial fleet into warships.
Yet, even as Venice achieved Mediterranean dominance, its power was already being undermined by global changes. The voyages of Bartolomeu Dias (1488) and Vasco da Gama (1497) rounded the Cape of Good Hope, opening the sea route from Atlantic ports to the Indian Ocean spice producers. Simultaneously, Christopher Columbus (1492) and John Cabot (1497) opened up trans-Atlantic trade. This pivot established the Atlantic, rather than the Mediterranean, as the world’s most important body of water for trade.
The massive demand for preserved food to supply these long voyages, coupled with the Catholic Church’s strict enforcement of “lean days” (Fridays and Lent, encompassing about half the year), ensured that salt became the foundation of this new Atlantic economic era. This shift permanently tied the fortunes of Northern Europe to the fish that thrived there, especially cod and herring.
The story of salt is a testament to how human necessity dictates ingenuity and conquest. Just as the Mediterranean was defined by the geometric precision of the successive evaporation ponds and the salty breezes that cured the Prosciutto di Parma, the next chapter of history would be defined by the fierce struggle to acquire the salt needed to preserve the “Friday’s treasure” harvested from the cold Atlantic waters.