Answer by Stephen Tempest:
Mongol success in battle depended on several factors, which combined to make them an extremely effective force. Still, they were not invincible, as the battle of Ain Jalut in 1260 proved.
- Tactically, Mongol horse archers were deadly in battle. Their horses allowed them to stay out of reach of the enemy, while their composite bows allowed them to rain down accurate fire. When the enemy army was disorganized and broken up by the losses from the archery fire, the Mongol heavy cavalry would charge in with lance and sword to finish the job.
- The Mongols were, compared to most other armies in the time period, extremely well-organized and disciplined. For most commanders from other nations, it was an achievement simply to get all their men to agree to fight the same enemy. A Mongol general could rely on his troops to carry out complex plans involving encirclements, flanking maneuvers, and feigned retreats.
- On the strategic level, the Mongols were extremely mobile. Soldiers had three or four horses each, allowing them to keep up a sustained movement rate far faster than an army traveling on foot, or even with a limited number of horses, could achieve. The Mongols were also used to living off the land, so they were not tied to a slow-moving supply train.
- Finally, the Mongols were willing to exploit the abilities of their subject races. From the Chinese, they recruited large numbers of mechanics and skilled engineers, who allowed them to make catapults and other siege engines to capture fortified cities.
So those were the Mongol advantages. How to counter them?
The most obvious method is to use the terrain to your advantage. Historically, the Mongols met their most serious defeats in the deserts of Palestine, the jungles of Vietnam, and the ocean between Korea and Japan. Their army was best suited to the steppes, where there was plenty of grass for their horses to graze on and wide, open spaces for them to carry out the broad outflanking moves they excelled at. In deserts, jungles, mountains, or thick forests, their mobility would be limited, their horses would suffer, and they could be tied down to a fixed point and defeated.
Unfortunately, such a strategy rather depends on having such terrain in the country you're trying to defend. How then to defeat the Mongols if you have no such natural advantages?
Most importantly, try to train your army to the same standard of discipline and organization as the Mongols themselves. The best plans will be useless if your subcommanders ignore them and decide to do their own thing in the name of honor and personal glory, or your troops break and run right off the battlefield through their terror of Mongol savagery.
Make sure you have effective scouting and reconnaissance, too. If the Mongols are ravaging the countryside, the peasants of your own nation should be willing to help provide information on their locations and numbers. Encourage them, listen to them, and set up a system to feed this information into your headquarters. Station riders with fast horses who know the countryside well to bring you news of where the Mongols are at all times. Their fast outflanking maneuvers will be less effective if you know where they are: Instead, perhaps you can ambush them, as Baibars did at Ain Jalut.
When the battle begins, you need troops who can defeat the Mongol horse archers and lancers. This is where the longbow and heavy crossbow come into their own.
Take two equally fit and equally well-trained archers. Have one of them bouncing around on the back of a moving horse; have the other standing with both feet firmly planted on the ground. Which of them will be most effective? The foot archer, of course. He can also use a larger and more powerful bow. He's a smaller target than the combination of a man plus a horse. And he can carry a large shield or have someone else stand in front of him holding a shield. (That's how the ancient Persians defeated horse archers back in their own day—regiments of archers with shield-bearers standing in front of them. Not very effective against Macedonian pikemen, but deadly against Central Asian cavalry.)
The one disadvantage of foot archers is that they can be vulnerable if the cavalry decide instead to charge home with the lance instead of sniping with the bow. How to defend against this? One way is to do what the English did at Agincourt—hammer thousands of sharp wooden stakes into the ground in front of their lines to form an impenetrable hedge of sharp points facing the enemy cavalry. Or combine your archers with a force of heavy infantry, such as pikemen. Their armor and shields will protect them from the Mongol archery, while they form a defensive line for your own archers to shield them from cavalry charges.
These combined arms tactics would be perfected by Europeans in the 16th and 17th centuries, after handheld firearms were invented; but there's no reason why you couldn't organize a tercio or battalion formation with archers instead of musketeers.
Combined-arms tactics to use against horse archers were already 1,000 years old when the Mongols invaded. They just needed training and discipline to be effective.
The one big disadvantage of such an army is that being on foot is comparatively slow-moving compared to the Mongols. Their best response is to avoid battle and keep their distance while attempting to surround me and cut me off from my sources of supply. How to counter this?
The obvious approach is to have wagons full of supplies and spare arrows at the center of my army or at the rear if my flanks are protected—that's how Richard the Lionheart defeated Saladin at Arsuf. With my supplies with me, I can outlast the Mongols. This is expensive—few medieval kingdoms could afford such a measure, as opposed to just living off the land—but it's the best strategy.
Alternatively, I need to force them to attack me head-on. How? Well, the Mamluks won at Ain Jalut through trickery: They sent a small force to bait the Mongols into attacking them, while the rest of their army lurked in the nearby hills ready to swoop out once the enemy was committed to battle.
An alternative approach, which is a classic strategy in 19th-century warfare, is to identify some target which the enemy cannot afford to lose, and move to attack it. They are therefore forced to attack you—at a time and place of your choosing—or else stand by and watch you capture or destroy your objective.
This strategy is tricky against a nomadic enemy like the Mongols, but they still had cities under their control. A powerful, slow moving army carrying its supplies with it could move into their territory and burn their cities, challenging the Khan to come out and fight it. Alternatively, if you attack in high summer, you can set fire to the grasslands on which their horse herds depend. Of course, such a measure will hurt the Mongols' subject people too, who might be your own citizens—so this strategy is a ruthless and cruel one. Still, the Mongols themselves employed cruelty deliberately as a strategy of war, trusting that their opponents would be more squeamish than themselves.
What about a long-term policy? Here, it's instructive to look at how the Mongols were eventually defeated and conquered by the Russians. Their weapon was the ostrog, or small fortress. A defended military post would be established in Mongol territory, with a secure supply route back to the heartland (preferably by sea or river, so the Mongols couldn't cut it). Of course the Mongols could lay siege to the fortress, but that would mean concentrating their army together in one place where your superior forces could attack and defeat them.
If they didn't attack, then you would attack them. Beat them at their own game—send out raiding parties of light cavalry to ravage, pillage, and burn the Mongol lands and, most importantly, kill their horses. These cavalry raiding parties were the origin of the famous Cossacks. When the Mongols struck back, the Cossacks would retreat back to the safety of the fort and dare the Mongols to attack them.
Eventually, the Mongols would get tired of their horses being killed and retreat further back into the steppes. At which point, you would build another ostrog deeper into the steppes and repeat the process, while the previous fortress became the core of a new city.
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