Depends on the battlefield. A narrow Alpine mountain pass would be a Roman victory whereas any open area would be Mongol victory.

If the Romans don't have their formation broken, they'd always win. It took a lot to beat them anyway. Like those two said, I'd assume the Mongol troops would win based on the given situation, but if the Romans could advance without serious threat - say like above, on a narrow Alpine pass - then I would say the Romans have a better shot.

"They would be slaughtered."

QFT

However the Roman Empire could potentially adapt. Maybe. If some of their best generals were on the job. Their fortified cities and fortresses and siege tactics might have saved them.

If they got lucky.

Here's a fun match-up:

Rome vs Han China in 200 BC. Go. Who wins this war? Lol.

This is easy! By the time the Mongol Hordes came around, if Rome maintained itself as a dominant force as it was when it was, they would easily have controlled most of Africa, India, Siberia, and even possibly parts of the Americas. Not to mention that they would have nuclear technology and could easily blow the hell out of some pitiful little Mongolians.

Thucy, Mongols were also siege experts though

Yep. Definitely what Atom said. He's right. He's absolutely right about how Rome would have had nukes in 1250. I agree completely. Without equivocation. Full confidence in what Atom said just now. Just read his post, why are you reading mine. Mute me and unmute him if you know what's good for you.

Depending on what time frame, Santa - they learned it all from the Chinese, and, if I'm not mistaken, the Romans were better at it than the Chinese. Plus the Mongol cavalry would have a hard fight in walled towns.

Still though, the Mongols could easily have toppled Rome had they came as they came to Europe in the thirteenth century in 200 AD instead.

http://en.wikipedia.org/wiki/Battle_of_Carrhae#The_battle

this is what would happen

Don't disagree but also remember the Huns were able to run riot at the heart of the roman empire

I think the Mongols would let the Romans have their cute little pass and ride around to whatever it is they're supposed to be defending. Hooray mobility. Mongols got it. Horse archers are simply nothing to fuck with.

I'm pretty sure Ventidius crushed the Parthians at the peak of their power. Mounted archers? The Mongols had trouble even beating the Song.

As they've said above, depends on the battlefield.

Also, I think the commander makes a difference--

If it's Caesar leading those legionaries, I'd have to take the Roman legions in a bloody one, just because they were so resilient.

That's not the fight I'd have wanted to see, though, *I* would want...

Ghengis Khan vs. Alexander the Great.

For me, THAT is the ultimate East Meets West showdown...

Two of the most successful commanders in history, unbeaten or nearly so.

I'd take Alexander there, but wouldn't that be something?

I think a lot of people are correct. First, the Romans were a full century earlier than the Mongols, and their technological advances, had the Empire endured and flourished, I think would have made the Mongols push overs.

Location of battlefield, also very important. If it is ONE battle, I think I may give the edge to the Mongols. If it is a prolonged conflict, I think Rome comes out on top.

The Mongols fought with a more advanced style of cavalary than was known to the Roman's or Alexander the Great's armies. Unlike the Romans the Mongols would have used stirups and saddles with a solid tree which made the rider far more secure on the horse making spears much more effective and making it easier to use a bow and arrow. On an open plain the Mongols would have had the advantage, especially as the Romans would not have been used to fighting such an army. Its an unfair comparison though - the Mongols were from the steppes, which is the perfect environment for raising horses. The horses could live off the land and the mongols could live off the horses. So they could field a huge cavalary. Off the steppes their advantage was diminished. (Of course the Mongols recruited their conquered peoples armies as they went and were able to adapt their tactics as the terrain changed). Throughout the ages nomadic people of the steppes have frequently represented a threat to their more civilized and sedentary neighbours. Many times in history peoples from central asia have wreaked havoc across Eurasia. It really took the invention of gunpowder and muskets before their threat was ended entirely.

I wonder how the mongols would have faired against an army of English lomgbowmen (the kind which cut the French knights to pieces at Crecy)?

Or Mongols against the Cheyenne (American Indians)? Their weaponry was superior to the U.S. army's pistols and civil-war era guns up until the six-shooter and ?quick reloading rifles were developed. And they were superior horsemen--They didn't stand still waiting for canisters of shot to hit them from cannons. And unknown to most--they were the only Indians to shoot from horseback, no matter what the American cowboy movies show. Like the Mongols, they could shoot while retreating, repeatedly. They also had that hang-onto-the-side-of-the-horse thing going, which shielded them as they rode in.

Are y'all kidding me? If we're talking a real Mongol army, not something like the glorified scouting expedition the Mamelukes fought to a bloody draw at Ain Jalut, but a real killing machine commanded by the Great Khan himself, or Subedei or Jebe like the armies which ensured that the Persian areas of central and southwestern Asia did not exceed the GDP they had in 1215 CE until the 1950's, against a Roman horde commanded by Marius, Caesar, or Agrippa (the best Roman commander of the era would have to be one of those three, right?), and the Mongols would utterly destroy them, ten times out of ten. All of you prattling on about it mattering what sort of terrain the fight takes place on are ignoring one very simple difference between the two: the Mongols are a cavalry force with the capacity to fight a siege and a tradition of excellent scouting and spycraft, whereas the Romans are pretty much just infantry and basic artillery (given that their Numidian auxilliary cavalry would be chased away in about 16 seconds) with next to no tradition of scouting whatsoever. Between the superior mobility of the Mongols, their advance knowledge of pretty much any terrain upon which they fought (the exception again being Ain Jalut) and the fact that the Romans could not maintain any sort of logistical tail (anything lagging a day or more behind the main Roman army would just wind up feeding and supplying the Mongols, considering who easily and regularly outider detachments would wind up looting it), there's no way the battle would be fought on any grounds not of the Mongols' choosing, unless they were trying to capture Rome itself and the battle was fought in the Italian peninsula itself, within a day's march of Rome or Mediolanum. There'd be a brief battle, while the Mongol achers on their tough steppe ponies turned the legions first into tortoises, then pincushions, and then there'd be about a two or three day trail of dead bodies heading off in whatever direction the Mongols chose to allow the routed Romans to retreat so as to utterly break their army, and a small handful of legionaries would trickle back home to spread news of the catastrophic defeat and awesome nature of their foes.

The interesting question, to me, is not whether the legions could defeat the Mongols (they couldn't), but whether Tilly's tercios could. Now, one of the advanced Thirty Years' War armies, the Empire under Wallenstein, the Swedes under Gustavus, Torstenssen, or Oxenstierna, or the Spanish under the Cardinal-Infante, would have enough firepower and mobility to deal with the Mongols, provided they could live off the land, but a slow moving tercio might not be able to deliver enough of a punch to the Mongols to knock them out.

People are usually overestimating the power of Roman legions. If you replaced any side at Crecy with Romans, they would receive some proper trashing unless they came in far superior numbers. Better weapons, better horses, stirrups et al. for the French and incredible range and armor penetration for the English. Against French, the legions would either hold formation to protect the cavalry from completely trampling them and die slowly to continuous charges or they would loosen up to use their pila to actually score some kills only to feel the power of a frontal charge some 3 seconds later. The English would probably decide not to fight solely on foot but to withstand longbow volleys, Romans would either try to advance in testudo only to realize that their thin shields were severely tested by bodkin arrows or tried to close the distance by marching in a more quick formation at which point they would have to be really fast so as not to be completely decimated.

Of course, Romans would just say whatevs and throw another 8 legions at you but that is related to the efficiency of the war machine, not actual performance in pitched battles.

"I think the Mongols would let the Romans have their cute little pass and ride around to whatever it is they're supposed to be defending."

This is true but I wanted to give Romans at least some chance ;) Although they had their difficulty with holding formation in such tight areas, Teutoburg being a somewhat related example.

again, comparing apples to oranges here. A european Empire, 1000 years (or more) earlier in history than a Steppes Empires.

"All of you prattling on about it mattering what sort of terrain the fight takes place on are ignoring one very simple difference between the two..."

Sure the Mongols were great and would have annilated a roman army in battle (I did say their cavalry was more advanced than anything the romans would have known), but they would still have needed to feed their horses in a sustained war. On the steppes they had a never ending supply of fodder. But into mountainous and wooded Europe they would have had to come up with fodder. They could eat the conquered farmers grain for a while but after while that would have run out. Great as the Momgols were their greatest advantage was on the steppes. How else cold they sustain such a large cavalary?
From memory I don't think they conquered southern china (I probably should check this but its late and I must goto bed). Why not? It was wrong terrain for them (or so I have read).

... should have checked. According to Wikipedia the Mongols did conquer souther china. I was wong about that. Don't know where I got that idea from. I must be thinking of some other invaders.

As terrible as it sounds, I kind of have to agree with King Atom and Stressedlines here.

If the Mongols had come at 50BCish as they came to Europe over a Millennium later, sure, the Mongols would have kicked some serious ass. If the Roman Empire had lasted until the Mongols actually came, they would have been by far the dominant power in the world, and probably would have had something close to modern technology, and the Mongols would have been quickly obliterated if they had been able to come into existence at all.

It's not a great comparison.

The Roman Empire actually lasted until 1453. Really the Byzantines were the romans.

The Mongols didn't have any trouble coming up with fodder when they defeated the Hungarians and took Buda and Pest. In fact they campaigned in the winter and took the Hungarian plain and devastated Poland with an invading army of under 50,000. Europe has supported armies of that size easily. The Mongols under Kublai Khan conquered southern China, and even built a fleet that defeated the Song fleet.

By the time the Byzantines were the Romans, the Roman Empire was already in serious decline. I'll amend that to "if the Roman Empire had remained in a similar form to that in the time of either the late republic, the early empire, or the five good emperors, they would have been by far the dominant power in the world..."

@Emac - you've mentioned Poland and Hungary. Both are plains, very similar to the steppe. I think this really does o down to geography. If the battle took place in France, Germany, or just a wooded area, much of the advantage the Mongols had in the range of their bows would have been wiped out. Plus (assuming the Romans are defending) the Romans would have felled trees to get in the way of their horses and done some significant damage with their siege weapons. Those could outshoot any bow. So I would say if the Romans were in a wooded area on a ground prepared by them, and if the Mongols didn't wait and starve them out, then the Romans would have a shot at defeating the Mongols. Not a great one, but a shot.

Also, I think it might have been spyman who asked this, but the Mongolian composite bows far outshot the English longbows. English would have had no chance.

As for the tercio vs. Mongols. I think it would be a stalemate. The Tercio formation would have held its ground suffering severe losses, but I don't see how the Mongols could break it.

After Heraklios I, there was very little Romanness to the Byzantines. I mean, when I think about what made Rome Rome, the first things that come to my mind are the trade networks and roads. The Mediterranean was a Roman lake in a way that the Byzantines, especially after the rise of the Caliphate, could only dream of. During the classical Empire, it didn't really matter whether you were in Arelate, Ariminium, Antioch, or Alexandria, the ties that bound you to the Empire were fairly similar. By the time the Caliphate rose, most of the Empire was a backwater, excepting Constantinople, Alexandria, Antioch, and charitably, Thessaloniki. The patterns of trade, land use, and military recruitment and doctrine had changed so drastically from the classical Principate that calling the Byzantines "the Roman Empire" was essentially merely a matter of glomming onto the prestige of the old Empire; a nearly-complete misnomer. The Empire that Basil II Bulgaroktonos (my personal favorite of the Byzantine Emperors and a serious badass) ruled over would have benn as incomprehensible to a Principate-era Roman as it would be to us.

@Goldfinger-

That's what makes the comparison between Tilly's tercios and Subedei's army so fascinating. I mean, say what you will about Tilly's infantry (utter scum that would make Charles Taylor puke with their sadism), they could absorb damage. It took an absolutely murderous artillery crossfire to break them at Breitenfeld. but their weaponry, other than artillery, was probably no better than the laminate bows that the Mongol archers used, given the difference in time spent training. But the tercio was designed to fight on the same kind of ground that the Mongol army excelled at. The tactical flexibility afforded by the structure and doctrine of the Mongol military would have been a powerful advantage. I think it's plausible that the tercio was the last European army that the Mongols could have beaten, but I think it's possible that the could have (tercios were awfully sensitive to threats to their baggage train, and Subedei would have that raided and sacked as automatically as he would have breathed-probably moreso, given what a fatass Subedei was).