In The Washington Post, Genghis Khan was named as "the most important man" of the last millennium. By barbarous criteria, it was an unanswerable choice. Genghis Khan conquered more people than Napoleon or Alexander. He ordered and inspired more massacres than any other tyrant before Hitler and Stalin. He destroyed more states, razed more cities, demolished more monuments, uprooted more fields than any predecessor. He left at his death an unequalled reputation for lust and bloodlust. "My greatest joy," he was remembered for saying, "is to shed my enemies' blood, wring tears from their womenfolk and take their daughters for bedding."
If recent research in Oxford's biochemistry department is to be believed, he was one of history's most philoprogenitive studs, with 16 million living descendents. Meanwhile, he made the streets of Beijing - according to an imaginative eye-witness - "greasy with the fat of the slain". His tally of victims in Persia amounted to millions.
In the long run, however, he was a constructive destroyer. His empire , at his death in 1227, spanned Eurasia, creating havens of peace around the silk roads and steppelands. Accelerated contacts enriched Eurasian civilisations. Technologies that trans- formed Europe's future - gunpowder, the blast furnace, paper money - arrived in the West. Traditions of scientific empiricism, dormant in Europe since antiquity, revived as Westerners began to share attitudes to nature formerly confined to China. Italian merchants, French craftsmen and Franciscan missionaries met in the depths of the Gobi.
It all might have happened anyway: trans-Eurasian trade had begun to grow in the previous century. Europe's "scientific renaissance" might have thrived on unaided stimulation from contacts with the Muslim world. But Genghis Khan's "Mongol Peace" made cultural cross-fertilisation possible on an unprecedented scale.
We know maddeningly little about about him. Today, his memory is twisted between myths. In Mongolia, under Communism, he was an almost unmentionable "deviationist" who detracted from the "peace-loving" image Mongolians tried to project. Now he is a national hero. In his own day, he toyed with similarly contradictory images: a warlord who intimidated enemies into submission by massacre; an avenger of insults to his dynasty and tribe; an embodiment of Mongol convictions of superiority over sedentary peoples; a scourge of heaven, divinely appointed to chastise a wicked world; a law-giver and architect of enduring empire.
In surviving documents, he addressed different audiences with conflicting messages. To Muslims, he was an instrument of God, to the Chinese a candidate for the Mandate of Heaven, to Mongols a giver of victory and of the treasure it brought. When he addressed monks and hermits he stressed his own asceticism. "Heaven is weary of the inordinate luxury of China," he declared. "I have the same rags and the same food as cowherds and grooms, and I treat the soldiers as my brothers."
When he appealed for sages to help him govern, "I have not myself excellent qualities for governing," he wrote - aping the mock-modesty of the mandarins. In 1219, a Taoist magus answered his call, crossing the Gobi desert, through "mountains of huge cold", where travellers smeared their horses with blood to discourage demonic assailants. When at last he reached the Mongol headquarters at the foot of the Hindu Kush, the khan's first question was, "Master, what is the secret of eternal life?"
John Man unashamedly confronts the dearth of sources by interpolating passages of personal experience. He gives us a first-rate travel book, not so much a life of the khan as a search for him: full of frustrations with frontier transport, vivid descriptions of otherness, and encounters with amusing cicerones. Man swims in the Yellow river, through water "thick enough to eat". Following the route of the khan's last campaign in China, he finds, at the "Treasure Mountain", "a couple of aged guardians with gold teeth and glasses held together with massive hinged clasps". In the museum of Guyuan, after "tea and noodles", he is surprised to see an ancient Persian vase, decorated with scenes of the siege of Troy. He interpolates a recipe for a Mongol casserole, cooked over a fire of dried dung: "First shoot your marmot... Into your marmot-skin bag, insert meat and red-hot stones... Ignore attached dung, ashes, etc." He interrogates peasants for the place of the khan's burial, tacking between discarded insights and short-lived enthusiasms, until only legends are left.
In places he retreats into "imagining" what Genghis Khan might have felt. But most of the time, he relies on spirited recapitulations of the earliest narrative sources. This is unsatisfactory, because the original texts have infuriating jump-cuts and non sequiturs.
Man's reconstructions, though tentative and teasing, are always lively and argued with élan. His excursions are sometimes over-elaborate: the last third of the book drags along after the khan's death. Much useful context is missing: there are under-exploited sources for the reconstruction of life at Genghis Khan's court and the role of power-women in influencing the politics of his seraglio.
The laws the khan encoded are an important and neglected source. To understand his rise, we need to know more not only about the khan himself, but also about the dynamics of pastoral society in the steppes, and the pressures that made the Mongols unite. But Man has scholarly gifts as well as acute intelligence and a winning way with words. This is a fine introduction to the subject, as well as a rattling good read.
Three big matters of judgement are worth questioning. First, Man thinks Genghis Khan had no ideology - only a sense of heaven-sent personal destiny. But the khan was the declarer and perhaps deviser of a justification of universal empire that continued to animate Mongol conquests for centuries: the doctrine that "as there is one sky, so there should be one empire on earth". The Mongols practised shamanism, but also cherished a shadowy religion of transcendence, worshipping Tengri, "the eternal blue heaven" that stretched between the horizons they saw across the steppe.
Secondly, Man has succumbed to the khan's charisma, endorsing the legend of his precocious vocation for power. Yet one of the big unresolved problems of Genghis Khan's life is why his talents remained inert or under-exploited for so long before his conquering career took wing. The imperial vision grew on him only gradually, as he felt his way from raiding, tribute-gathering, and exacting ransom to constructing empire with permanent institutions of rule.
Tradition alleges a turning-point: when a subordinate suggested exterminating 10 million Chinese and turning their fields to pasture for Mongol herds, Genghis Khan realised that he could profit more by sparing the peasants and taxing them. Yet it was a tentative process, of which the khan himself may have been only dimly aware as he extemporised his way to greatness.
Finally, Genghis Khan gets the credit for the Mongol blitzkrieg. But he spent 23 years subduing northern China. After his death, Mongol armies leapt beyond their natural, cavalry-friendly environment, conquering paddy-scored lands, impressing huge forces of foot, organising siege-trains and fleets, appropriating the full potential of sedentary economies to finance further wars. If Genghis Khan was "the man of the millennium", it was only because he inaugurated an enterprise and adumbrated a vision which his successors fulfilled.
Felipe Fernández-Armesto's new book 'So You Think You're Human?' is published this month by OxfordReuse content