I remember reading an interesting article that asserted that Genghis Khan, the conqueror, considered Europe as a backward, shitty place not worthy of his attention. Since he and other foreign conquerors largely ignored them, Europe didn't face much external strife and conflict and it was also able to get access to science and knowledge from the more developed countries of the period (Genghis Khan cared about science, and ensured that all knowledge was collated and shared from all conquered regions, in his empire). This helped Europe develop unnoticed, at a much faster pace than other countries.

Mongols raided Europe several times starting around the 1220s, but at that point they were overreaching. For example, they were defeated and pushed back during their campaigns in modern day Germany and Austria.

Europe also faced the Umayyad invasion starting in the 8th century.

> This helped Europe develop unnoticed, at a much faster pace than other countries.

Many of the most important trading ports at the time were in Europe. How would they be “unnoticed”?

> Mongols raided Europe several times starting around the 1220s ..

That was Genghis Khan's son and the Mongols conquered Romania, Bulgaria and Hungary and held control of Russia and Ukraine (interestingly, Genghis Khan conquered Russia in winter, something that neither Napolean nor Hitler could do). Compared to the wealth and culture of the developed kingdoms of that period, Europe didn't fascinate even his descendants. While some of them did plan to conquer Italy, Austria and Germany (after reaching up to Hungary), they abandoned the plan after the then "Great Khan" died, and they had to withdraw to decide on the next successor. Kublai Khan (grandson of Genghis Khan), for example, was more fascinated by China's wealth (said to be the richest empire of its time) and population, and spent his focus on conquering it.

While Mongolian conquests were brutal, the peace in their empire allowed the silk road trade routes to be opened between aAsia and Europe. This allowed cultural exchanges and trade between them that led to Europe's progress. Land routes in Central Asia was instrumental in connecting Europe to Asia, and the peace in the Mongolian empire was instrumental in allowing trade to flourish. The sharing of knowledge and information was encouraged in the Mongolian empire and this also helped Europe get access to some fundamental technologies like paper making, printing, gunpowder manufacturing etc. that would have have a tremendous impact on humanity.

> How would they be “unnoticed”?

Their lack of wealth and development during that period didn't make them an attractive target for conquest.

If you look at where Mongols succeeded and failed (notably they didn't control Northern Russia directly, rather keeping them as vassals/raiding occasionally - but they also +- failed in Indochina, India, etc.), it's all about terrain. Logistics of the Mongol armies became much less tenable in non-steppe terrain... I was actually wondering what would have happened had Ogedei not died when he did, as far as Europe is concerned... but then, the Eurasian Steppe mostly ends around modern Ukraine :)

It seems that your whole proposition is based upon the notion that the hordes were unstoppable, and only retreated out of self interest. This contradicts the fact that mongols were defeated in East and Central Europe, and retreated right after. It also dismisses the historical trading routes in the Mediterranean sea, and direct access to Northern Africa and the Atlantic ocean.

Still, European powers were at a constant war of conquests with Islamic kingdoms from Northern Africa and Middle East.

Bottom line, your idea contradicts centuries of war in Europe.