The key to the military success of the Mongols was their extraordinary army which consisted entirely of cavalry — soldiers on the back of fast Mongolian horses. Although all men up to the age of 70 were conscripted, the army comprised no more than 100,000 men and often they were divided into several armies that operated independently of each other. What they lacked in numbers, they made up for in terms of speed and mobility. For one thing, they had no supply train. Instead the soldiers carried strips of dried meat and curd with them in their saddle bags which they would eat while on the move. Each soldier had access to several horses which he could switch between. The horses would graze on the land which they covered and they could themselves be eaten by the soldiers, milked, or tapped for blood to drink. Dead soldiers would simply be left to decompose where they fell and be picked at by wild animals, in accordance with Mongol custom. In addition the Mongols had no slow-moving engineering corps. Instead the engineers built what they needed — bridges or assault machines for attacking city walls — with the help of whatever material they found on the spot. The Mongol armies were used to fighting in winter when most other armies took time off; they could wade rivers at night; and their horsemanship was of course second to none. As nomads they had been on horseback since they were toddlers and the Mongol warriors were particularly notorious for their ability to fire off arrows, or use their lances, while in full gallop towards the enemy. Their bows were so tightly strung it took two men to do it.
The Mongols used different battlefield tactics too. They fought sneakily and with no regard for chivalric conduct or fair play. A favorite ruse was to feign defeat and to beat a retreat. As the enemies came in pursuit of them, they would be ambushed and picked off one by one. Another ruse was to make an assault at night, and make fires which made the army look far larger than it was — and then to attack from all directions at once. The Mongols were also notorious for using hostages as human shields by marching them in front of their own forces. Battlefield tactics such as these required discipline and a high level of coordination among the troops. These skills were initially hones during the hunts, known as nerge. The Mongol chieftains would organize vast hunting parties, comprising thousands of participants, which encircled herds of deer and other prey, driving the animals before them as they gradually tightened the circle. As each man quickly learned, any failure of discipline and coordination allowed the prey to escape. On the battlefield these lessons were adapted to military use by commanders who relied on torches, whistling arrows and flags to direct their troops. The chief aim of the Mongol generals was to strike terror in the enemies. To loot a city in a spectacular manner was not only a way of getting one’s hands on treasure, but also, and above all, a way of sending a message to the people in the next town that all resistance was futile. However, in relation to the cities that surrendered peacefully the message was equally clear: as long as you behave yourselves, and faithfully pay a ten percent tax, your assets will be safe and your inhabitants protected.
After Genghis Khan’s death in 1227, his sons and grandsons continued these conquests. In 1235, his son, Ögedei, who replaced him, called in a kurultai to decide on the future direction of their foreign conquests. After some debate it was decided to make a move on Russia and Europe. Subutai, the leading general, had been the first to discover Europe in the 1220s, and he had already tested the military capabilities of the Russians and found them wanting. When the new campaign began in 1236, Subutai set his sight on the Volga river, inhabited by the Bulgars, and this was where a three-year long campaign began. The Mongols quickly discovered that the Russian city-states were divided amongst themselves, and moreover that they were only weakly defended. In accordance with their custom, they began by dispatching envoys, asking the Russians to submit willingly. Few cities took up the offer, however, and those that did not were attacked. Ryazan, 200 kilometers southeast of Moscow, was the first in line and in December, 1237, the city was thoroughly looted and sacked. From here the Mongols moved on to Kiev, the main city in Russia at the time. The city was captured in December, 1240. “Kiev had been a very large and thickly populated town,” Giovanni de Plano Carpini, a diplomatic envoy, reported back to Rome in 1246, “but now it has been reduced to almost nothing, for there are at the present time scarce two hundred houses there and the inhabitants are kept in complete slavery.” In the end only a few towns, such as Novgorod and Pskov in the north, survived the onslaught. One long-term consequence was that Kiev lost influence throughout Russia and that Moscow gained. The prince of Muscovy, who sided with the Mongols, acted as an intermediary between the foreign invaders and the various leaders of the Russian city-states.
The Mongol armies, meanwhile, continued on into Europe. In the spring of 1241, in a two-pronged attack, they simultaneously moved into Poland in the north and Hungary in the south. The Europeans, like everyone else, were entirely taken by surprised but eventually a combined army of Czech, Polish and German knights was assembled against them. They met at Legnica in Poland on April 9, 1241, and at Mohi, Hungary, two days later, and in both battles the European armies were destroyed. [Read more: The Mongol invasion of Europe] The Mongols continued swiftly across eastern Europe and into the lands of the Holy Roman Empire, and the scouts which preceded them came right up to the city walls of Vienna. This was when news reached them from Mongolia that Ögedei Khan had died and that a kurultai once again was to be assembled to elect a new leader. Since Ögedei’s brothers all recently had died too — either in battle or under some distinctly suspicious circumstances — it was clear that the title of khagan this time would be given to one of Genghis Khan’s grandchildren. Since several of the potential candidates for the job were engaged in the European campaign they had quickly to return to fight for the position. Despite the brilliantly executed campaign and their decisive victories, the Mongols left Europe never to return. Perhaps Europe was too far away, perhaps there was not sufficient forage for the horses, or perhaps there was simply not enough treasure to loot in a Europe which was poor compared to other parts of the world.
In Russia the Mongols maintained a presence in the new capital they built for themselves on the Volga, named Sarai, which quickly became one of the largest cities in the world with some 600,000 inhabitants. This was where the princes of Russia showed up to pledge allegiance and to receive their jarlig, a tablet which identified them as legitimate rulers recognized by the Mongol khan himself. In the latter part of the thirteenth-century this Russian part of the Mongol empire, known as the Golden Horde, came increasingly to assert its independence, and they begun to come into conflict not only with external enemies but also with other parts of the Mongol lands. But it would take until 1480 before the various Russian princes finally assembled a united army that was strong enough to be able to defeat them. Even then, however, instead of simply disappearing, the Golden Horde broke up into smaller political units which soon took their place among the Russian city-states. In 1556, Sarai was conquered and burned, but the successor-states lived on, in particular the Mongol khanate on the Crimea peninsula which was annexed by the Russian state only in 1783. The last descendant of Genghis Khan to rule a country was Alim Khan, the emir of Bukhara, who was deposed by the Soviet Bolsheviks in 1920, exactly seven hundred years after his celebrated ancestor first occupied the city. [Read more: Alim Khan and Russian imperialism]