It's a sad testament to the true human spirit that nations and regions continued to slaughter each other in combat and war even as the Black Death ravaged the countrysides and cities of Europe. Estimates have placed the reduction of the overall population by the Plague at roughly half the inhabitants of Europe, and even if these are liberal estimates, they reflect the deadliness of the disease.
Whether the Black Death was a visitation of divine wrath, or whether it was simply the result of bad hygiene and unwholesome conditions, the fact is that it put the epidemics and pandemics of modern times to shame. No one was safe, there was no hope of containment, and once you were infected your time on earth was short. The Plague arrived from the East around 1346 and peaked between 1348 and 1350, but its impact was devastating.
Responses were about what one would expect from the Middle Ages: certain people groups were persecuted, others were quarantined, a variety of medical practices more rooted in superstition than science were performed. Maybe the strangest development was the masks worn by doctors, large iron helmets resembling birds' heads with incense burning in the beak to cleanse the air and make it breathable. To see those cloaked and helmeted figures roaming the streets must have been almost as terrifying as getting the plague.
It was strange times for the West. The Arabs had re-introduced Europe to higher learning when the two groups clashed during the Crusades, and scholars were renewing their interest in Classical texts from ancient Greece and Rome. At the same time, big wars and petty fights continued to rage, and these were exclusively struggles for power or preeminence, and not ideologically based as so many modern wars supposedly are.
The Late Middle Ages were in many ways the birth pangs of a territory about to undego thorough reinvention. The Renaissance (which means "rebirth") overlapped and outlived the Late Middle Ages, but stood on the shoulders of the previous era. The Medieval appeal to authority was the basis for the human-centered rationalism of the Renaissance, but once that rationalism was established the former system was abandoned.
Maybe the most significant event of 1300-1450 came during the Hundred Years' War, fought between 1337 and 1453 between England and France for control of the French throne. Joan of Arc was a peasant girl with no training outside the home who showed up at the Siege of Orleans in 1429 saying she'd had visions and could lead the French to victory because God had showed her how.
And this was a difficult problem for the French. Her appeals to authority were wholly supernatural, but her bold military leadership and strategizing were more than effective, and led to several important victories that effectually weakened the English armies until they eventually withdrew. The Church burned her as a heretic, but the French people loved her as a true heroine.
It was a classic example of the tension that relying on either authority or reason exclusively produces. The Church leaders couldn't admit that Joan had seen visions from God because that would undermine their authority, but the military leadership and skill she demonstrated was desperately needed to accomplish the temporal goal of ousting the English.
Eventually, the Protestant Reformation was able to rectify these problems, and show that both reason and revelation work together to reveal the truth to humans, and that neither one stands wholly alone. In the meantime, Europe was left trying to answer the burning questions, like why was the Black Death ravaging them?, and the Church was giving them misleading, false, or vapid answers. It only remained for men like John Calvin and Martin Luther to step in, proclaiming the truth found in God's Word regardless of its political or cultural implications.