The Mongol Empire

Temujin’s achievement before any conquest was internal. Steppe society was organised by clan and lineage and had always fragmented along those lines. He broke it deliberately, redistributing followers into decimal military units of tens, hundreds, thousands and ten-thousands that cut across tribal loyalty and answered to appointed commanders promoted on merit and proven loyalty rather than birth.

That reorganisation is why the empire held together after conquest, and it was ratified at the kurultai of 1206 where he was proclaimed Genghis Khan. The yassa, a body of decrees attributed to him, regulated the confederation, and its provisions on religious freedom and on the treatment of envoys were enforced with characteristic severity.

The Mongols governed conquered territory through the people they conquered. Chinese, Persian, Uyghur, Khitan and Muslim administrators ran the fiscal and bureaucratic machinery. In north China Yelu Chucai argued successfully that taxing peasants produced more revenue than turning their fields to pasture, and Persian officials administered Iran under the Ilkhans. The empire had no administrative tradition of its own and simply hired one.

Succession was the structural flaw. Every khan’s death required a kurultai to elect the next, so campaigns halted and armies went home. That is one reason Europe was spared in 1242, when the advance into Hungary stopped on news of Ogedei’s death. After Mongke the mechanism failed entirely, and the empire divided permanently into four rival khanates.

The Mongol army was built on a skill every steppe child learned, shooting a composite bow accurately from a moving horse. What Genghis added was organisation, discipline and intelligence. Units drilled to signal, the feigned retreat was a standard manoeuvre rather than a desperate one, and campaigns were preceded by systematic reconnaissance through merchants and envoys.

Mobility was the decisive advantage. Each man rode with several remounts, could subsist on the move, and covered distances that European and Chinese commanders did not believe possible, which meant Mongol armies repeatedly appeared where nobody had planned to defend, and converged from separate axes on a schedule agreed months earlier.

The critical adaptation was siegecraft, which steppe armies traditionally could not do. The Mongols solved it by capturing engineers. Chinese and Persian specialists were absorbed and moved across the empire, so Chinese siege technology was used against Persian cities and Persian counterweight trebuchets against Chinese ones. Subutai, the outstanding commander of the age, ran campaigns across Russia and central Europe with a coordination that has been studied ever since.

Terror was deliberate policy, as in Assyria. Cities that surrendered were spared and taxed, and cities that resisted were destroyed and their populations massacred, with the news carried ahead by refugees and merchants. The arithmetic was made legible on purpose, and it greatly reduced the number of sieges that had to be fought.

The Pax Mongolica is the empire’s most consequential achievement and the hardest to weigh against the killing that produced it. With the steppe under a single authority, the overland routes between China and the Mediterranean became safer than at any time before or since, and the volume of exchange rose accordingly.

The instrument was the yam, a relay system of post stations at intervals of a day’s ride, staffed and provisioned by local populations, where a rider bearing a paiza tablet of authority could exchange his horse and continue. Messages crossed the empire at speeds few pre-modern states ever matched, and the same network carried merchants, envoys and missionaries.

The Mongols favoured trade actively. Merchants had low status in Confucian China and high status under the Mongols, who taxed commerce rather than suppressing it, invested in caravan partnerships, and standardised weights and customs. Under Qubilai, China ran on paper currency, which astonished Marco Polo more than anything else he saw.

The same network carried what nobody wanted. The Black Death moved west along the routes the Mongols had secured, reaching the Crimea in the 1340s and Europe from there. The plague travelled the same roads as the silk, and nothing in the Archives shows more clearly that connection carries harm as readily as goods.

Mongol society before the empire was pastoral, mobile and organised around the extended household and the herd. Sheep, goats, horses, cattle and camels moved seasonally between pastures, wealth was measured in animals, and status in followers.

Women held a position that startled every settled observer who encountered it. Mongol women managed the household economy and the herds, rode and hunted, and appeared in public and in council. More significantly, they held political power: Sorqaqtani Beki, widow of Genghis’s youngest son, secured the succession for her sons Mongke and Qubilai through decades of patient manoeuvring and is arguably the most consequential political figure of the second Mongol generation. Regencies by widows governed the whole empire more than once.

The conquests moved people on a vast scale, and not only as captives. Craftsmen were systematically spared and relocated. A Parisian goldsmith ended up building a silver drinking fountain at Karakorum, and specialists of every kind were sent wherever the khan wanted them.

The demographic cost is disputed. Contemporary chroniclers give figures for massacres that are demographically impossible, and modern estimates of total mortality vary enormously. What is not disputable is that some regions, Khwarazm and parts of Iran and Iraq among them, suffered destruction of population and irrigation infrastructure from which they did not recover for centuries.

Mongol religion was shamanic and centred on Tengri, the eternal blue sky, with the khan ruling by Tengri’s mandate, an idea structurally similar to the Chinese Mandate of Heaven and probably related to it. Shamans mediated with spirits, and Genghis is said to have gone alone to a sacred mountain before major decisions.

The policy toward other religions is the unusual part. The Mongols exempted clergy of every faith from taxation and military service, protected places of worship, and made no attempt at conversion, partly from indifference and partly from a real belief that prayers from every tradition were worth having. Christian, Muslim, Buddhist and Daoist clerics competed for favour at Karakorum, and the Franciscan William of Rubruck describes a formal debate staged between them before the khan.

The khans’ own families reflected it. Sorqaqtani was a Nestorian Christian, and her sons ruled a Buddhist-leaning China and a Muslim-conquering Iran respectively. Religious identity was not yet a political constraint.

That changed as the khanates settled. The Ilkhans in Iran and the Golden Horde converted to Islam, and Qubilai’s line patronised Tibetan Buddhism in China. Within three generations the universal empire had become four regional states, each taking on the religion of the people it governed. The conquerors were absorbed by the conquered, which is the standard fate of steppe empires and the reason they are so often underestimated.

The Mongols built little and did not need to, which makes this the least conventional entry under this heading in the Archives. A mobile society’s architecture is the ger, the felt tent on a wooden lattice frame, portable, warm and structurally ingenious, and its art is what can be carried: metalwork, harness fittings, textiles, jewellery.

Karakorum, the imperial capital founded by Ogedei, was a modest walled town by Chinese or Persian standards, notable mainly for its cosmopolitanism and for the tree-shaped silver fountain built by the captured Parisian goldsmith Guillaume Boucher, which dispensed four different drinks. It was abandoned when Qubilai moved the centre of gravity to China.

The empire’s real artistic significance is as a conductor. Chinese motifs such as dragons, clouds and lotus appear in Persian manuscript painting. Persian ideas about blue-and-white decoration met Chinese porcelain technology and produced blue-and-white ware. Islamic metalwork forms turn up in China. The Ilkhanid manuscripts produced at Tabriz, above all the great illustrated Shahnameh, are among the finest books ever made, and they are unthinkable without the movement of artists that the conquests forced.

Under Qubilai, Yuan China built on a Chinese scale. Dadu, the capital on the site of modern Beijing, was laid out on a grid that still shapes the city, and the grand canal was extended to supply it.

The Mongols had no writing when the empire began. Genghis adopted the Uyghur script for Mongolian after capturing a Naiman scribe, and the resulting vertical script served the administration and survives in Inner Mongolia today.

Their contribution to knowledge was as movers rather than makers, and its scale is easy to underestimate. Persian astronomers worked at the Maragha observatory under Ilkhanid patronage, where Nasir al-Din al-Tusi and his colleagues produced planetary models that reappear in Copernicus. Chinese astronomers worked alongside them, and the exchange ran both ways.

Medical, agricultural, cartographic and military knowledge moved in the same way. Chinese medicine reached Iran, and Persian and Arabic works reached China. The Ilkhanid vizier Rashid al-Din compiled a history of the world, with sections on China, India and Europe drawn from informants from each, which is arguably the first attempt anywhere at a global history.

Gunpowder is the transfer with the longest consequences. Developed in China, deployed by Mongol armies, and appearing in European sources within decades of the Mongol campaigns in eastern Europe, its westward movement is difficult to trace precisely and hard to explain without them.

The Mongols are documented by everyone they attacked, which produces an unusually complete and unusually hostile record: Chinese, Persian, Arabic, Armenian, Georgian, Russian, Latin and Japanese sources, all describing the same people from the receiving end.

The one substantial internal source is The Secret History of the Mongols, composed in Mongolian shortly after Genghis’s death and preserved, oddly, through a Chinese transcription made to teach the language. It is an unusually candid document, an account of Temujin’s rise that includes his humiliations, his flight from captivity, his killing of his own half-brother over a fish, and the deteriorating relationship with his closest friend Jamukha. Nothing else in the Archives presents an imperial founder in that register.

Persian historians under Mongol rule, Juvayni and Rashid al-Din above all, wrote detailed histories with access to Mongol informants and archives, and wrote as servants of the dynasty, which shapes what they emphasise. Their casualty figures in particular have been treated far too credulously.

The historiography has swung hard. Older Western scholarship treated the Mongols as an inexplicable barbarian catastrophe, and a revisionist wave since the 1980s has emphasised the Pax Mongolica, the exchange, the religious tolerance and the administrative sophistication. The current position tries to hold both, an empire founded on mass killing that also produced the most connected century the pre-modern world had seen.