The 14th century was, according to the contemporary historian Barbara Tuchman, "born to woe" (A Distant Mirror, pg. 24). It began in the clutches of feudalism, where most of the people were desperately poor and malnourished. According to the Malthusian principle, the population was about to reach a critical mass where demand would overstep supply and create an economic crisis. The century had begun with a chill in which the Baltic Sea froze twice and the years that followed would be filled with horrible storms and unseasonable cold. The weather cycle of the planet was entering what would later be known as the Little Ice Age. This odd climactic change provided a perfect opportunity for the germs that caused the Plague to enter the human population by disrupting the feeding cycles of the fleas who carried the disease. At the time, however, the contemporaries could know little of this. What they worried about was the loss of certain crops in Scandinavia, the closing trade channels with Greenland due to the freezing of the ocean, and the shorter growing season. The food crisis became ever greater. Crops failed all over Europe, resulting in widespread famine. Tuchman records, "Reports spread of people eating their own children, or the poor in Poland feeding on hanged bodies taken down from the gibbet" (A Distant Mirror, pg. 24). The Cambridge Illustrated History of the Middle Ages tells us that, "The ninety years from 1340-1430 share with the tenth and twentieth centuries the dubious honor of being one of the most violent periods in the history of Europe. Violent not so much due to the bloodshed, the blind cruelty, or the reigning injustice, which were indeed present, but to the harshness of daily existence, the complete uncertainty about the future. 'I never knew a single year in my village without troubles, war or death,' an old man would say on his deathbed in Charles VII's reign" (Fossier, pg. 52). Next, throw into the mix a plague of unrivaled proportions, a pandemic to end all others: the Black Death.
The Black Death Part 3: A Description of the Disease