In Europe, four plagues claimed thousands of lives and destroyed four empires: they changed the course of European history, namely Milan plague, Seville plague, Vienna plague and Moscow plague. These four plagues spread widely, affected a large number of people and had far-reaching influence, and were notorious in European history.

The Great Plague in Milan occurred during the bloody "Thirty Years' War", and the Germans brought the plague to Italy. After infection, the plague was brought into central and northern Italy by the Venetian army. Since then, Milan, the most prosperous city in northern Italy, has fallen into a great plague. Around this plague, a total of 280,000 people were killed.

The plague in Seville was the death knell of the Spanish empire, which made Spain fall into hegemony and put down its posture to make peace with its old enemies. The plague that lasted for several years claimed the lives of 500,000 people in Spain, which made Seville's economic strength plummet and completely loosened the rule of the Spanish colonial empire.

The great plague in Vienna destroyed Vienna, saved the endangered cities from the invasion of the Ottoman Empire, and preserved Christian civilization. Unlike the plague that broke out in the war, it broke out from the garbage accumulation and dirty environment in Vienna. It even swept through the Ottoman Empire that invaded Central Europe by plane, and eventually the Ottoman army completely collapsed.

The great plague in Moscow caused the Kremlin to be almost conquered, and the czar's rule was in jeopardy. The plague that broke out in the Russian-Turkish war spread violently after the strong concealment of Russian generals and the desperate filling of soldiers. In the mass chaos, the Kremlin was almost captured by citizens.