Around 1300–1350 the Medieval Warm Period gave way to the Little Ice Age. The colder climate resulted in agricultural crises, the first of which is known as the Great Famine of 1315-1317.The demographic consequences of this famine, however, were not as severe as those of the plagues of the later century, the Black Death. Estimates of the death rate caused from one third to as much as sixty percent. By around 1420, the accumulated effect of recurring plagues and famines had reduced the population of Europe to perhaps no more than a third of what it was a century earlier. The effects of natural disasters were exacerbated by armed conflicts; this was particularly the case in France during the Hundred Years' War. As the European population was severely reduced, land became more plentiful for the survivors, and labor consequently more expensive. Landowners attempt to forcibly reduce wages, these efforts resulted in nothing more than fostering resentment among the peasantry, leading to rebellions such as the French Jacqueline in 1358 and the English Peasants' Revolt in 1381. The long-term effect was the virtual end of serfdom in Western Europe. In Eastern Europe, on the other hand, landowners were able to exploit the situation to force the peasantry into even more repressive bondage. While the Jews were suffering persecution, one group that probably experienced increased empowerment in the Late Middle Ages was women. The great social changes of the period opened up new possibilities for women in the fields of commerce, learning and religion. Yet at the same time, women were also vulnerable to incrimination and persecution, as belief in witchcraft increased.
Through the Welsh Wars the English became acquainted with, and adopted the highly efficient longbow. Once properly managed, this weapon gave them a great advantage over the French in the Hundred Years' War. The introduction of gunpowder affected the conduct of war significantly. Through the Battle of Crécy in 1346, firearms initially had little effect in the field of battle. It was through the use of cannons as siege weapons that major change was brought about; the new methods would eventually change the architectural structure of fortifications. Changes also took place within the recruitment and composition of armies. The use of the national or feudal levy was gradually replaced by paid troops of foreign mercenaries. The practice was associated with Edward III of England and the condottieri of the Italian city-states. All over Europe, Swiss soldiers were in particularly high demand. At the same time, the period also saw the emergence of the first permanent armies. It was in Valois France, under the heavy demands of the Hundred Years' War, that the armed forces gradually assumed a permanent nature.
Though the Catholic Church had long fought against heretic movements, in the Late Middle Ages, it started to experience demands for reform from within. The first of these came from the Oxford professor John Wyclif in England. Wycliffe held that the Bible should be the only authority in religious questions, and spoke out against transubstantiation, celibacy and indulgences. In spite of influential supporters among the English aristocracy, such as John of Gaunt, the movement was not allowed to survive.
Trade and commerce
Portuguese and Spanish explorers found new trade routes – south of Africa to India, and across the Atlantic Ocean to America. As Genoese and Venetian merchants opened up direct sea routes with Flanders, the Champagne fairs lost much of their importance.
Among the innovations of the period were new forms of partnership and the issuing of insurance, both of which contributed to reducing the risk of commercial ventures; the bill of exchange and other forms of credit that circumvented the canonical laws for gentiles against usury, and eliminated the dangers of carrying bullion; and new forms of accounting, in particular double-entry bookkeeping, which allowed for better oversight and accuracy.
With the financial expansion, trading rights became more jealously guarded by the commercial elite. Towns saw the growing power of guilds, while on a national level special companies would be granted monopolies on particular trades, like the English wool Staple. The beneficiaries of these developments would accumulate immense wealth.