There were not enough workers to tend to fields and such, so thus the remaining were able to demand more rights.
The bubonic plague or black death
The Black Plague hit Europe and when it ended it is estimated that half the population perished.
It was the Bubonic Plague (Black Death).
Black plague 3/4 of Europe died.
Black Death Plague was pandemic during 1346 to 1353. It killed 75 to 200 million people.
The Bubonic Plague (a.k.a The Black Plague) caused a dramatic decline in the population of Europe in the 1300s.
The plague peaked in Europe during 1348-1350. The plague began in the late 1320's and 1330's and resurfaced on multiple occasions until 1738.
150 years
The Black Death killed almost half of the population of Europe and Britain.
Europe
Asia
The first recorded epidemic of the Black Death / Bubonic Plague was in Europe during the 6th Century. The disease truly became pandemic in 1328