Medieval Times: The Mongols and the Plague By Jillian Hilwig
Genghis Khan rises to the top of the Mongol empire and starts conquering land.
Gengis Khan made fake promises about good things he would do if other empires surrendered to him. If they didn't agree, the Mongols would catupult infected bodies into the empires, weakening them with disease and making it easy to conquer the empire.
Gengis Khan and the Mongols conquer fourteen million miles!
When the Mongols went to Europe, rats came on their boats with infected fleas on them. The fleas on rats carried the plague to Europe.
The rats spread the plague all over Europe, people were very scared. The infected people were carried away in a cart to keep them from infecting other people.