Besieging the Black Sea port of Caffa, the Mongols began to fall to the invisible arrows of a plague that had followed the Silk Road from the arid plains of central Asia. While the Genoese they wanted to capture were safe within the city, Mongol bodies piled up outside its walls.
The Mongols of the Golden Horde then did something unprecedented in both the history of warfare and the history of disease. They piled their dead into catapults and hurled them over the city walls, raining diseased corpses on the besieged Genoese. These Italian merchants—visitors at the edge of the Mongol Empire—boarded their ships to flee the Crimea. It seems they brought the plague home with them.
"If this account is correct," writes bacteriologist Mark Wheelis in a paper for the Centers for Disease Control, "Caffa should be recognized as the site of the most spectacular incident of biological warfare ever, with the Black Death as its disastrous consequence."
A century later, the population of Europe was only half the size it had been before the plague came west.
King of the Black Death
But even if the disease reached Europe by way of the late Mongol Empire, causing what Wheelis calls "the greatest public health disaster in recorded history," ultimate blame for the cataclysm may not fall to the Mongol khan or his soldiers. Instead we should look to the conduct of European monarchs—and one in particular.
"Focus on the devastation caused by outbreaks of the Black Death in the mid-14th century is partially correct but superficial," wrote Murray Rothbard in An Austrian Perspective on the History of Economic Thought, "for these outbreaks were themselves partly caused by an economic breakdown and fall in living standards which began earlier in the century."
The established wisdom agrees with Rothbard, to a point: A crippled economy weakened people's health and lowered their immunity, making them ever-more vulnerable to the coming pestilence. But the standard account is that the Little Ice Age and the resulting Great Famine brought an end to the flourishing economy of the High Middle Ages, thereby weakening human immunity while allowing rats to thrive.
There is little doubt that cold weather and crop failure can cause great harm, but changes in the natural world don't tell the whole story.
Before the black death, the first three centuries of the millennium had experienced a commercial revolution in Europe. What we now call the High Middle Ages saw trade, production, and finance blossom. Living standards rose significantly, and the institutions of early capitalism developed and spread through western Europe.
This growing, healthier economy was the result not just of new competition within the market but of competition for political rule. "There was a balance between the power of Church and State," according to Rothbard, "with the Church slightly more powerful."
While the religious and secular authorities struggled in stalemate, Europe’s productive classes innovated and reconnected across the ancient roads of the Roman Empire. Between the Atlantic sources of wool and linen cloth to the northwest and the Mediterranean sources of dyes, silk, spices, and coinage from the southeast, several Roman roads intersected in the region of Champagne, where the French king’s authority was still weak.
The counts of Champagne sponsored commercial fairs at these ancient crossroads. Outside the fairs, the counts policed the roads to ensure safe conduct for merchants to and from the burgeoning markets, but their role within the fairs was one of benevolent absence. These hubs of international commerce were free zones, untaxed and unregulated by kings or nobles. Competing private courts developed to resolve disputes and enforce contracts under a uniform body of private law, the lex mercatoria.
The commercial revolution, which grew in the gaps between church and State, between kings and nobles, was brought to an end in the era of the absolute monarchy. "The nation-state came to hold sway," Rothbard wrote, "breaking the power of the Church, taxing, regulating, controlling, and wreaking devastation through virtually continuous war for over a century."
Among the new breed of fourteenth-century monarchs—these creators of the rising nation-state—Philippe le Bel of France deserves special opprobrium.
His one goal in life was to expand his power, both on the continent and within his own kingdom. When Pope Boniface objected to Philippe's new taxes on the clergy, Philippe had the pope seized in Italy and prepared to try him for heresy. When the aging pope died before his trial, the king seized the papacy itself and brought it from Rome to France, where he could keep it under control.
To finance the international trade of the High Middle Ages, merchants had turned to the moneylenders among the Jews and the Catholic Order of the Templars. Deeply in debt himself, Philippe expelled the Jews, had the Templars declared heretics by the captive French papacy, and seized the funds of both for the royal treasury. After these confiscations, merchants would have a harder time raising money for their ventures. The market for commercial loans suffered what economic historian Robert Higgs calls "regime uncertainty." No funds were safe from the voracious monarchy.
Philippe acquired Champagne through marriage and ended every aspect of the region's traditional commercial freedom. He levied heavy sales taxes on all trade and banned his territorial enemies from the fairs, crippling the sources of wool and linen.
The king's endless wars did less lasting damage through direct bloodshed than they did by establishing regular taxation in France.
In A Distant Mirror: The Calamitous 14th Century, historian Barbara Tuchman writes that the 1300s bore the "hoofprints of more than the four horsemen of St. John's vision." After plague and war, the third apocalyptic horseman she lists is taxes.
When goods had crossed Europe, people grew healthier and richer, and the population increased. When the king grew more powerful, he destroyed the independence of his nobles, the authority of the church, and the viability of the financial institutions that had become the lifeblood of the once-thriving economy. He put an end to the steady growth in his subjects' standard of living, weakening their general health well before the black death came west.
The merchants abandoned their overland routes and took to the sea. The trading ports in Italy and on the Atlantic continued to thrive economically while the rest of Europe declined.
Plague may have descended from Asia as colder weather crept down from the north, but the poverty that weakened the medieval peoples of Europe and helped to spread disease and starvation was less the product of Mongol warfare or climate change than of the growth and centralization of political power.
As Murray Rothbard put it, "The causes of the great depression of western Europe can be summed up in one stark phrase: the newly imposed domination of the State."