A post from Quora on the likelyhood of a Mongol conquest of the kingdoms of Western Europe. http://www.quora.com/Did-the-Mongol...i-not-died-just-before-launching-his-invasion Tim O'Neill, I have a M.A. in Medieval Literature ... (more) 628 upvotes by Simon Thompson, Ved Mundora, Quora User, Jae Won Joh, (more) Despite what breathless History Channel pop-documentaries and Mongol fanboys would have you believe, probably not. Yes, anyone who has done even the most cursory reading on the large-scale punitive raid into Europe 1240-41 AD will know that the Mongols caught the eastern Europeans by surprise and dealt them serious defeats in the field at Liegnitz and at Mohi through superior tactics and generalship. But no, this does not mean that this army would have conquered Europe if it had not been recalled (it was too small). Nor does it mean that a much larger force is likely to have done so either. There are a number of clear historical reasons this would have been unlikely: 1. Geography, logistics and historical precedents Firstly, the Mongols were not the first Eurasian horse nomads to attack Europe, though they were the first who had done so for several centuries. From the Third Century to the Ninth Century western Europe has seen the Sarmatians, the Huns, the Alans, the Avars, the Khazars and the Magyars all emerge from the steppes and invade, usually via the plains of the Hungarian Basin. Some of these peoples made it as far west as what is now France and Italy, but none managed to establish a permanent foothold west of what is now the eastern Balkans. This is because of geography and the logistics of horse nomad battle tactics. Beyond the Hungarian Basin, Europe becomes totally unsuited to large horse armies. There simply isn't the pasture to sustain the string of 5-15 remounts needed for a nomad warrior to maintain the kind of lightning campaign that could give them a strategic advantage over the armies of sedentary cultures. Attitla's Huns established a large hegemonic "kingdom" based on the Hungarian plains with its core further east on the Ukrainian steppes, but his "invasions" of the Western Roman Empire were little more than massive plundering raids and shows of strength. They quickly ran out of steam once the Huns got too far from large supplies of fodder for too long. Later nomad horse armies ran into the same problem. Avar and Magyar raiders inflicted crushing defeats on western European armies, but were never able to follow up with any kind of invasion or occupation. Ottonian German feudal armies learned that the further a Magyar horse army got from its steppe base the more vulnerable it became. People with a knowledge of the terrain of modern Europe find this difficult to grasp. They see wide open countryside, rolling hills of farmland and can't understand why a Mongol army of the kind that had conquered similar pastoral countryside in China could find Europe so impossible. But Europe in the Thirteenth Century did not look like Europe today. Most of that open countryside was still thickly forested; and not the highly cultivated, open, park-like "forest" of modern Europe, but mainly thick wildwood forest of a kind modern Europeans never see outside of some national parks in eastern Poland. This was not nomad horse-army country. Those modern rolling hills of farmland were impassible by horse and those strings of 5-15 remounts would be dead from starvation within a few weeks. Any Mongol army foolish enough to try to force its way through this terrain would soon find itself having to walk back though hostile territory, with most of its horses dead. And there goes the famous Mongol tactical superiority. 2. Western European Strategy and Tactics in the Thirteenth Century Strategy and tactics develop in a given context. This means that while the Mongols' art of war developed on the steppes and suited that context, the armies of feudal Europe developed in the far more enclosed and constrained terrain of their context. What worked on the plains of Eurasia and could be adapted to China and Russia would not work well at all in western Europe. And this is not just a matter of the lack of fodder and room for wide strategic manoeuvre discussed above. A combination of factors (terrain, political fragmentation, logistics) meant that war in western Europe from the Third Century onward had led to a lower emphasis on large-scale, set piece battles and the development of a warfare of manoeuvre, skirmish and siege, with field battles usually on a smaller scale and mainly only when one side with a clear advantage caught the other on the hop. Many wars were fought with no open battles at all, though with a lot of harrying, skirmishing, manoeuvre and many sieges. This meant that from the Ninth Century onwards, Europe became a land of castles and the art of fortification and the corresponding art of siege warfare were both raised to increasing heights of sophistication. This is why in the two centuries before the Mongol invasion of Europe, Medieval Europeans were able to hold the Crusader Kingdoms in the "Outremer" despite being overwhelmingly outnumbered - masterpieces of the art of fortification like Kerak, Montreal and Krak des Chevaliers were based on centuries of perfecting the art of castle building. In a fortress like those or their equivalents across Europe, a populace could wait until a besieging army simply starved itself into having to withdraw. Those who note that the Mongols were good at siege warfare underestimate precisely how good they would have to be to conquer western Europe. Yes, Mongolian use of Chinese siege tactics could storm fortresses (though Chinese siege tactics were inferior to those of western Europe in key respects). But in Europe they would have had to mount thousands of such sieges, bogging down their armies for months at a time with every single one. The sheer number of castles in Europe in this time is staggering - in 1241 they numbered in the many tens of thousands. And combined with the terrain and the logistical problems already noted, they would represent an almost endless succession of obstacles that a Mongol army intent on conquest would simply not have the capacity to overcome. Bypassing them would only work in the short term and doing so consistently would be nothing more than a large-scale raid. Ottonian Germany showed over and over again that it could always defeat the Magyars in the long term by retreating into castles and then harassing the bogged down nomads through the forage-free forests. And while people make a lot of the victories of the Mongols in Hungary in 1240, we hear much less about the disastrous Golden Horde Mongol campaign in 1285. Learning from the 1240 campaign, the Hungarians had defended their kingdom with a network of western European-style castles. Unable to take them all, bogged down and constantly attacked, a depleted Mongol army began to retreat and was intercepted and comprehensively defeated at Pest by Ladislaus IV and then finally destroyed on the retreat home. This, rather than the earlier campaign in Hungary, gives us an insight into the reception a Mongol invasion would have received further west. 3. Religion and Politics in Western Christendom In the sudden and unexpected blitzkrieg of the Mongol incursion of 1240-41, the politically fragmented nature of western Christendom worked in the favour of the invaders. The various rival states of Europe were in no position to mount any kind of short-term co-ordinated response and what response was thrown together - eg by the Teutonic Order in response to the incursion in Poland - was small scale and piecemeal. Some argue that this fragmentation means that western Europe would have been easy pickings for the Mongols, who had readily conquered much larger polities and so would have picked off the divided kingdoms of Europe. In fact, the fragmentation of Europe was actually to its advantage, at least at first. Larger, more centrally-organised and more cohesive polities had fallen to the Mongols very quickly because of the rapid capture of a central capital, the defeat of a supreme leader or the capitulation of two or three vital centres, they precipitated the collapse of resistance. In Europe, the fall of Hungary and Poland may have caused alarm further west, but it had no greater impact than that. If the Mongols had managed to annex Croatia or even parts of the jigsaw of states that made up the German Empire, this would have had no effect elsewhere. And as the points above make clear, that piecemeal approach would not have been as easy as some armchair generals make out. Then there is the fact that western Christendom would not have remained disunited for long. Two hundred years earlier a much less rich, less populated and less militarily sophisticated western Europe had sent a succession of allied armies thousands of kilometres east to capture, against the odds, wide swathes of territories in the Middle East. The religious fervour of the Crusading movement had led to remarkable military feats and victories against the odds by armies from all over Europe, united by a fanatical zeal for (as they saw it) the defence of their faith. This zeal was still strong in the Thirteenth Century, so the idea that western Christendom would not harness that ideological power in the face of a threat not only to their homes but also to their local holy places - pilgrimage sites, holy shrines, cathedrals and monasteries - in the face of invasion by pagan hordes is unthinkable. And that level of religious fanaticism goes a long way when it's combined with patriotism and the protection of vested interests. The Mongol invasions of Syria and Mamluk Egypt were crushed by a similar combination and, along with the difficulties already noted above, this would be a massive force multiplier for the defenders of western Christendom. Conclusion While it is possible to argue any hypothetical either way, the idea that the Mongols would simply roll westward to the sea is rarely based on a detailed analysis of the relevant factors. No other horse nomad invader managed a permanent extension of territory much beyond the Hungarian Basin, and for good reasons. The Mongols were more numerous and more militarily powerful than any of those predecessors, but the obstacles facing any longer term conquest of Europe were so formidable that it is highly unlikely they would ever had done more than inflict some short-term if devastating raids beyond Hungary. Medieval Europe would have been too tough a strategic nut for them to crack.