[konjin]

Because Egypt was conquered by the Mamluks and Andalusia by the Spanish at the same time. There was no area under Muslim control that was not ruled by barbarians whose idea of hygiene was washing their posterior every time they crossed a river.

The Mongol invasion was a unique event in Eurasian history. They make every other invasion and conquest seem tame by comparison. If you have a choice of facing Macedon, Rome, Napoleon, Nazi Germany, the USSR or the Mongols never choose the Mongols.

It was the first and only time a single power could have destroyed all other civilizations and came very close to it. To the point where they managed to destroy both the Polish, Hungarian and Romanian crusader armies within days of each other, with minimum casualties and would have continued depopulating Europe to the English Channel if the Khan had not died and the majority of the army returned home for a civil war.

The reason Europeans aren't riding horses fighting a rear-guard action against the Aztec conquistadors is because the Mongol court liked silks and perfumes enough to not raze every city they conquered.