The siege of Caffa is widely accepted as being the start of the Black Plague in Europe.
After a protracted siege, during which the Mongol army under Jani Beg was suffering from the disease, the army catapulted the infected corpses over the city walls of Kaffa to infect the inhabitants.
The Genoese traders fled, taking the plague by ship into Sicily and the south of Europe, whence it spread north.
Every comment you made about the Mongols is revisionist, every single sentence you made about them so far is exclusively positive.
You even managed to slip in securing roads and safe travel into them spreading the Plague.
At the same time, nearly every sentence you write about anything related to Europe is combined with something negative.
Then you accuse others of bias and prejudice...