The Bubonic Plague or Black Death is a deadly plague/ disease that swept throughout Europe between 1347 and 1351. The Black Death arrived in Europe through trade ships and killed over 20 million people. About 25-50% of Europe was dead.
The plague spread through the air and through bites from infected fleas and rats. Symptoms of the Black Plague include fevers, chills, vomiting, diarrhea, aches and pains, and death. They would also get black boils on their body.
After three years the plague epidemic fades out however, it did reappear every few generations for centuries. How the disease spread changed due to modern sanitation and public health practices but it was not eliminated. There was a serious labor shortage and workers demanded higher wages because so many people had died in Europe. This plague also affected churches because people did not understand why their prayers weren't being answered. Peasants ended up leaving their manors in order to try and find employment.