Hundred Years' Wat and the Black Death

 I've learned about the Hundred Years' Wat and Black Death in 'Understanding History of English Language'class. It was interesting to know that these terrible events actually helped English to be spread.
 As workers die out of the war and disease, workers became scarce. Therefore, nobels, who hadn't used English because it was considered to be low-grade, started to learn English to get workers.

 The Hundred Years' War was a series of conflicts waged from 1337 to 1453 between the Kingdom of England and the Kingdom of France and their various allies for control of the French throne, which had become vacant upon the extinction of the senior Capetian line of French kings. The House of Valois controlled France in the wake of the House of Capet; a Capetian cadet branch, the Valois claimed the throne under Salic Law. This was contested by the House of Plantagenet, the Angevin family that had ruled England since 1154, who claimed the throne of France through the marriage of Edward II of England and Isabella of France.
  The war owes its historical significance to a number of factors. Although primarily a dynastic conflict, the war gave impetus to ideas of both French and English nationalism. Militarily, it saw the introduction of new weapons and tactics which eroded the older system of feudal armies dominated by heavy cavalry in Western Europe. The first standing armies in Western Europe since the time of the Western Roman Empire were introduced for the war, thus changing the role of the peasantry. For all this, as well as for its long duration, it is often viewed as one of the most significant conflicts in the history of medieval warfare. In France, civil wars, deadly epidemics, famines and marauding mercenary armies turned to banditry reduced the population by about one-half.

 The Black Death was one of the most devastating pandemics in human history, peaking in Europe between 1348 and 1350. Although there were several competing theories as to the etiology of the Black Death, it has been conclusively proven via analysis of ancient DNA from plague victims in northern and southern Europe that the pathogen responsible is the Yersinia pestis bacterium. Thought to have started in China or central Asia, it travelled along the Silk Road and reached the Crimea by 1346.
From there it was probably carried by Oriental rat fleas living on the black rats that were regular passengers on merchant ships. It spread throughout the Mediterranean and Europe. The Black Death is estimated to have killed 30–60 percent of Europe's population, reducing world population from an estimated 450 million to between 350 and 375 million in the 14th century. The aftermath of the plague created a series of religious, social and economic upheavals, which had profound effects on the course of European history. It took 150 years for Europe's population to recover. The plague occasionally reoccurred in Europe until the 19th century.