Genghis Khan, the World Conqueror
In February 1220, after a siege of only fifteen days, the leading citizens of Bukhara opened the gates and surrendered their city to Genghis Khan.1 Only the garrison of veteran Turkish slave soldiers in the citadel held out, but these mercenaries were quickly overcome and massacred. In a brilliant strategic maneuver of deception, Genghis Khan and his youngest son, Tolui, had crossed the Jaxartes River (Syr Darya), while two other Mongol columns attacked Otar on the middle Jaxartes River and Khojend in the Ferghana valley, thereby confusing Muhammad Shah, the master of Khwarazm, as to Mongol intentions. Audaciously, Genghis Khan and Tolui at the head of fifty thousand horse archers headed southwest into the desolate Kizil Kum, moving swiftly from oasis to oasis. The Mongols then suddenly emerged from the desert to take the city of Bukhara by surprise from the southwest.2 Genghis Khan’s Chinese engineers immediately set to work battering the walls. The citizens of Bukhara were stunned because for the first time a nomadic army possessed engines that undermined walls. Refugees flocking into the city from the countryside reported that the Mongols had spared those villages that instantly submitted, but they destroyed those that resisted. Terror paralyzed the defenders; the patricians of the city soon treated for terms. The Persian historian Atâ-Malek Juvayni, writing in the reign of Genghis Khan’s grandson Hulagu, preserves or perhaps re-creates the proclamation of Genghis Khan, who spared the city from a sack, but deplored the great ones who had misled the people into committing the sin of resisting.3 Hence, the rich would have to surrender all their wealth in an organized shakedown rather than a wanton sack. Even so, craftsmen, physicians, and scribes were deported to Karakorum; provisions and war matériel confiscated; and young men conscripted into the Mongol army for its next operation, the assault of Samarkand, Bukhara’s sister city in the Zeravshan valley 160 miles directly east of Bukhara.4
Bukhara was the jewel of eastern Islam. The city lay on the Zeravshan River arising in the Pamirs and flowing west to join the middle course of the great Oxus River on its northwestern journey to the Aral Sea. Bukhara was thus always a major destination for caravans arriving from Kashgar after crossing the Pamirs or caravans arriving from Merv to the west. The Samanid emirs, deputies of the Abbasid Caliph in Baghdad, had adored the city with masterpieces of Iranian architecture during the ninth and tenth centuries.5 The Naqshbandi sufi order had flourished in this city since the twelfth century and its inspired holy ones had carried mystical Islam to the Turkish tribes of the central steppes.6
Even though Bukhara under the Karakhitan rulers had lost its primacy as the political capital and hub of international trade of Transoxiana, the city was still revered as the spiritual and cultural center of Eastern Islam. Its surrender was symbolic, but symbolic victories can be just as decisive as strategic ones in war.
Genghis Khan, now nearly sixty years old, must have been awed, and perhaps a bit unsettled, by what he saw. Bukhara lay at the extreme western edge of his world. He was familiar with the grandeur of the imperial cities of northern China, but Bukhara’s architecture was new and alien to him. The minarets of the medresses with blue glazed tiles dominated the skyline. Genghis Khan looked up 150 feet in wonder to view the Kalyan minaret, then just a century old, that towered over the religious heart of the city and gave a commanding view of the entire plain.7 He must have been amazed into reverence, for he ordered the minaret spared, but he directed his soldiers to level the surrounding complex with its great mosque because he mistook it for a palace of Muhammad Shah.
Over the next two years, the Mongols captured every major city on the Silk Road in Transoxiana, Afghanistan, Khurasan, and northern Iran.8 These victories stunned the world. Yet for all the brilliance, Genghis Khan did not wage this campaign as part of a grand strategy of world conquest. The vision of world conquest was a result not a cause of this campaign. Hence, it is often argued that the Mongol Empire started with the accession of Ögedei, for he framed the strategic plans of a world conquest.9 But, in my opinion, this view is misleading. The spectacular victories in 1220–1221 confirmed to, perhaps even inspired, Genghis Khan that the conquest of the world by the Mongols was not only possible but their destiny. Ögedei implemented the plans Genghis Khan would have pursued if he had lived longer. Hence, the triumphant entrance into Bukhara marked a turning point. For Genghis Khan, it gave him a new sense that his army could conquer any foe on the Eurasian continent. Yet this war that put the Mongols on the path to world conquest arose over an unanticipated, sordid, even trivial incident.
Fifteen years earlier when Temujin had been proclaimed universal lord, he had no plans for world conquest, and the fabled caravan cities of Muhammad Shah’s realm were far beyond the limits of the world known to Mongols.10 Temujin, now Genghis Khan, had more immediate concerns. Foremost, he had to make his power effective, and legitimate, after three decades of incessant fighting among the tribes. At the great feasting of the kurultai, Genghis Khan ostentatiously rewarded and promoted loyal officers (noyan) and warriors. He presided over rites to the ancestral spirits, invoking their protection for his warriors soon to set out on raids against recalcitrant forest tribes or border towns of the Jin Empire.11 All these celebrations required the blessing of the leading shaman Kokchu, whose father, Monglik, was shaman to Temujin’s father, Yesügei. Kokchu wielded great influence over the Mongols, because he was widely believed to ascend on a gray horse to the other world. In his mystical trances, he had long foretold the universal lordship of Temujin. The wily Kokchu, in effect, gave Genghis Khan his legitimacy in the eyes of many of the tribes, but Kokchu wanted more than spiritual authority. Within days of the celebrations, he conspired to overthrow Temujin.12 The ever-watchful Börte detected the traitors, and then warned her husband, who promptly summoned and arrested Kokchu. The shaman was executed in the customary fashion. Kokchu was wrapped in a carpet and trampled by Mongol horsemen lest the ancestral spirits be offended by the shedding of the blood of a holy one. Relations between khan and shaman had perhaps never been more than superficially cordial. After this incident, Temujin politely consulted diverse spiritual figures, but he took every measure to ensure that his authority was absolute.
Genghis Khan also took practical measures to consolidate his power. During the years immediately following the great kurultai, he steadily turned his warriors into an imperial army. Genghis Khan revolutionized the warfare on the steppes, first seen among the Scythians and Xiongnu, and tactically perfected by the Turks. He imposed discipline and organization that made the Mongol army into the finest of steppe armies, and one of the greatest fighting forces of all time. Genghis Khan organized his army into tactical units of ten, a method of reckoning employed on the steppes since the Xiongnu.13 The cavalry was based on an arban of ten men, who were, in effect, a military yurt or a band of brothers in arms. The ten arbanlar were grouped into a formation of hundred men known as jaghun; ten jaghunlar were grouped into a mingghan, a unit of one thousand men. Ten minggahanlar comprised a tumen of ten thousand men at a full strength. The tumen was a strategic unit that could operate as a column of a greater expedition (ordu) or as an independent army so that its strategic function was comparable to the corps of Napoleon’s Grande Armée.14 In organizing his army, Genghis Khan broke with previous practice of grouping units by clan, tribe, and language. Instead, his men were recruited into units without regard to origin, language, or religion; they were selected on the basis of their merit and loyalty.15 Officers and men ceremoniously pledged their life and honor to Genghis Khan because they accepted their salt from the Great Khan, and they toasted him by drinking his fermented mare’s milk qumis (or kumis). On the Eurasian steppes, warriors had long paid homage to their lord by accepting his salt, an invaluable commodity obtained in trade from the sedentary civilizations. Drinking of fermented mare’s milk (qumis) had long sealed oaths of brotherhood (anda) among warriors or signaled the submission of a ruler’s envoys to an overlord.16 Genghis Khan applied these traditional acts of homage to his entire army. Every warrior henceforth became sworn brothers (anda) to their lord Genghis Khan so that acts of disobedience were punished with the utmost severity.
Within this army of devoted warriors, Genghis Khan selected an even more elite force, his bodyguard (kashik) of ten thousand men, many of whom were appointed training officers at all levels for the tumenler.17 From the kashik, Genghis Khan and his heirs drew accomplished generals and subordinate officers based on loyalty and talent. Genghis Khan thus could dispense with clan and tribal leaders, who might challenge his authority. He entrusted command only to those men of proved loyalty, foremost his “four dogs of war,” who had shared his early adventures and dangers: Jebe, Sübetei, Jelme, and Bo’orchu. Within perhaps five years, Genghis Khan had transformed the Mongol and Turkish warriors of the eastern Eurasian steppes into an army imperial in its loyalty, and professional in its discipline, tactics, and ethos. His sons and grandsons would expand and improve this superbly disciplined army.18 Genghis Khan created an imperial army that outmatched every opponent of the Eurasian continent for the entire thirteenth century. At his death in 1227, the Mongol army numbered 129 tumenler or 129,000 horsemen—an extraordinary mobilization of manpower from a population of the Mongolian homeland that perhaps totaled between seven hundred fifty thousand and one million souls.19
Genghis Khan trained his imperial army so that he could maintain his authority across the eastern Eurasian steppes in the fashion of previous nomadic conquerors. The desultory fighting of the past thirty years disrupted trade with the cities of the Jin and Xi Xia Empires. Genghis Khan, just as much as Modu Chanyu, depended on this trade for silk, manufactured goods, and foodstuffs to sustain his people and his own power.20 Incessant raiding among the tribes had diminished the flocks and herds of livestock so essential to the nomadic way of life. As Great Khan, Temujin immediately approved great raids by his vassals, who seized great numbers of stock animals, plunder, and skilled captives in the Chinese borderlands. On the strategic level, in 1206, Genghis Khan was planning a far more ambitious reckoning with his ancestral foe, the Jurchen emperors of the Jin dynasty who had incited warfare among the tribes and backed foes of Genghis Khan. Genghis Khan aimed to wrest the prefectures of northern China, and impose his hegemony over the rump Jin Empire. But first Genghis Khan had to control the Ordos triangle, and so the entrance into the middle and lower Huang He, the heartland of the Jin Empire. The sinified Tangut-speaking emperors of the Xi Xia controlled this strategic region along with the Gansu corridor and the caravan cities of the eastern Tarim Basin. Genghis Khan was kept informed about Jin and Xi Xia courts by leading Khitans, Chinese, and Uyghurs who sought Mongol service.21 Genghis Khan soon learned that the Xiangzong, who had seized the throne of the Xi Xia in 1206, warred against the Jin emperor Wanyan Yongji, who reigned under the Chinese throne name Xingsheng (1208–1213).22 Furthermore, many Khitans, Chinese, and Uyghurs were ready to welcome a Mongol army that would overthrow the usurper Xiangzong.
In the spring of 1209, Genghis Khan attacked the Xi Xia in his first campaign waged outside of Mongolia. His army swiftly covered over 650 miles, including the final stretch of two hundred miles across the Gobi, to surprise the Xi Xia army. But Tangut generals, following the precepts of the memoranda presented to the Han emperor Wudi over thirteen centuries earlier, fortified the passes and they evacuated the civilian population behind city walls.23 The campaign soon stalled until reinforcements arrived from Mongolia so that Genghis Khan defeated the Xi Xia field army in a war of maneuver and skirmishing in late summer. In October 1209, Genghis Khan laid siege to Ningxia, the Xi Xia capital, but the Mongol army was inexperienced in siege warfare and suffered grievously from privation and disease.24 After a grueling siege of three months, Genghis Khan ordered the diversion of dammed waters to undermine the city walls, but the defenders sabotaged the operation so that waters instead flooded the Mongol camp. Genghis Khan, in frustration, negotiated. In January 1210, Genghis Khan accepted the submission of Xiangzong as a vassal, who sealed the deal with promises of a marriage alliance and tribute.25 The treaty held for the next fifteen years. Strategically, Genghis Khan henceforth gained free passage through Xi Xia domains to attack the Jin Empire. Even more important, Genghis Khan learned hard lessons in logistics and siege warfare. He immediately recruited a corps of Chinese engineers which accompanied the Mongol army on every future expedition.
In March 1211, Genghis Khan summoned another national kurultai on the banks of the Onon River and in view of the holy Khenti Mountains.26 In a magnificently staged spectacle, Genghis Khan harangued the Mongol nation in arms, denouncing the arrogant envoys of the Jin emperor Xingsheng who demanded Genghis Khan, just like his forefathers, render tribute to their golden emperor reigning in Zhongdu. The summoned nation of the Mongols roared its objections and declared war on the Jin emperor. Thereupon, Genghis Khan withdrew into solitude to consult the ancestral spirits and Eternal Blue Sky for three days. On the fourth day, he emerged to announce that victory was assured by divine favor. For Genghis Khan, a successful war against the Jin would be the capstone of his career. He would live on in legend as the greatest conqueror of the steppes, surpassing the deeds of his Xiongnu, Rouran, Turkish, and Uyghur predecessors. Genghis Khan dispatched twenty thousand horsemen to guard the western frontiers, while he himself commanded the rest of the national levy, reportedly sixty-five thousand strong, in an invasion of northern China.27 From the start, Genghis Khan planned a war of conquest with the ultimate objective the cities and fields of the Yellow River (Huang He). To many observers, Genghis Khan’s war appeared to be an act of folly. At best, the Mongol invasion would end up as another great raid with hauls of captives and booty, followed by posturing between Mongol Khan and the Jin emperor that would end up in a treaty restoring trade between the steppes and the cities of northern China. The Jin emperor Xingsheng ruled domains in wealth and population that were twenty to thirty times greater than that of Mongolia.28 He could field and maintain an army of five hundred thousand men, including one hundred twenty thousand cavalry.29 Yet the vacillating Xingsheng, seventh of the Jurchen emperors, was no match to Genghis Khan. His generals directed operations; most of the army was committed to garrisoning cities. The best of the cavalry units comprised tribal regiments of Khitans and Turks long disaffected with Jin rule. They were weary of the onerous drafts of their warriors to fight incessant wars against the Song Empire.30 The Öngüt Turks, who patrolled the arid steppes of Inner Mongolia north of the Great Wall, promptly went over to Genghis Khan and opened the way to China.31 As soon as the Mongols broke through the defenses of the Great Wall in June 1213, many Chinese and Khitan subjects of Xingsheng welcomed the Mongols.32 The princely brothers Ila Ahai and Tuka, former envoys of the Jin court, had switched their allegiance to Genghis Khan a decade earlier. They now persuaded many of their leading countrymen to embrace the Mongol cause. Once in northern China, Genghis Khan divided his army into columns that swept Jin domains, defeated Jin armies in detail, and accepted the surrender of many towns on terms over the next year. The indecisive Xingsheng desperately tried to negotiate, but Genghis Khan refused.33 Genghis Khan was determined to bring down the Jin house. He laid siege to Xijing (today Dotong in Shanxi), the western capital of the Jin Empire. Late in 1212, Genghis Khan himself was seriously wounded in the knee by an arrow during the siege.34 He turned over command to his youngest son, Tolui, but Tolui failed to press the siege and lost the initiative. A detachment of Jurchen soldiers slipped past the Mongol siege works and occupied the strategic Juyong Pass, thereby threatening to cut off the besieging Mongols from their lines of communication to their homeland. Tolui might have raised the siege and withdrawn, except the ever-bold Jebe retook the pass in a daring night attack.35 Xijing was doomed and fell soon after. In the autumn of 1213, the Mongol horsemen appeared before the walls of Zhongdu, the principal Jin capital. On September 13, 1213, the Jin general Hushahu murdered his discredited master in Zhongdu and declared a princely cousin of the emperor, Wanyan Xun, as the next emperor, Xuanzong (1213–1224).36 The treacherous Hushahu was soon murdered by officers loyal to the former emperor, and to the relief of the new one. Xuanzong, however, could neither oppose the Mongol army nor offer acceptable terms to Genghis Khan. In the summer of 1214, Xuanzong quit Zhongdu, and relocated his court to Kaifeng in the lower valley of the Yellow River.37 Meanwhile, Genghis Khan first blockaded and then besieged Zhongdu.38
Zhongdu, the Xanadu of Western travelers and poets, boasted one million residents, spacious parks, the fabled Daning Palace, and the beautiful artificial Taiye Lake, around which Kublai Khan would later center his palace when he rebuilt Zhongdu as his summer capital. Zhongdu was massively fortified, and defied the Mongol army for nearly a year. Genghis Khan had to fight off a major Jurchen relief expedition; his Mongols suffered from disease and the heat of summer, and then the blistering winter in 1214–1215. On May 31, 1215, the city fell to the Mongols only because Khitan officers of the Jin garrison betrayed the city by handing over the Lugao Bridge, vital to the defense of the southern approaches of the city.39 The siege had proved costly. In retaliation, Genghis Khan ordered his first large-scale massacre of a civilian population, and his horsemen were even directed to destroy the crops by riding over the cultivated fields of the surrounding countryside. Mongol warriors spent over a month looting Zhongdu and massacring its population.40 Allegedly sixty thousand virgins cast themselves from the walls to escape the ravages of the Mongol barbarians. Later visitors still reported hills of bleached bones around the city and a land drenched in a foul stench arising from the tens of thousands of decomposed bodies of unburied victims. To be sure, massacre was long the fate of the defeated on the steppes, but Genghis Khan deliberately ordered the destruction of Zhongdu and a massacre on such a scale to terrorize the remaining cities of northern China into surrender. The Jin court at Kaifeng was powerless to recover its capital, and the emperor Xuanzong braced for the inevitable Mongol invasion of the valley of the Huang He. But the invasion never came.
In the spring of 1216, Genghis Khan retired to Mongolia, and he entrusted the pacification and organization of the Chinese conquests (today Shanxi, Hebei, and Shandong) to his viceroy (guo-wang) Mukali.41 Genghis Khan, just like previous nomadic conquerors, planned to rule northern China through mandarin officials. He also could not afford to leave Xuanzong in Kaifeng, where the Jin emperor might parley with the Song emperor Lizong to make common cause against the northern barbarians. The Song court, however, failed to perceive a Mongol threat, but instead pursued a policy of pitting Jurchens against Mongols and applauded the defeat of the hated Jurchens.42 At this point, the Song court calculated correctly. While Genghis Khan waged war with tactical and strategic brilliance, as yet he pursued a traditional policy of gaining mastery over the borderlands of northern China. He did not contemplate a conquest of Song China, let alone world conquest. Instead, Genghis Khan prepared for a methodical conquest of the remaining Jin domains, and for another grueling siege of a Jin capital, Kaifeng. But a series of unforeseen circumstances diverted Genghis Khan’s attention to the west and ultimately brought him before the walls of Bukhara. He would not return to face his Jin rival until nine years later, near the end of his life.
Rebellions on the western and northwestern regions of his empire erupted in 1217. First, Genghis Khan swiftly punished an incipient revolt among his ancestral foes the Merkits by virtually exterminating the tribe.43 Meanwhile, Boroghul, an adopted son of Genghis Khan, was slain in an unsuccessful expedition against the Kori-Tumar forest peoples. Boroghul, a captive Jurchen infant whom Genghis Khan’s mother, Hoelun, had reared, had risen to high rank in the imperial guard. The wrathful Genghis Khan immediately turned the full might of the Mongol army against the rebels. He exacted a fierce vengeance.44 One hundred Tumar captives were sacrificed to the spirit of Boroghul. The Oriats peoples of the forest and nomadic Kyrgyz were terrorized into submission upon hearing the news of these Mongol atrocities.45 They dutifully furnished warriors to the imperial army. Genghis Khan now extended his sway far across the central Eurasian steppes to the pastures watered by the lower Yenisei and Irtysh Rivers. Immediately to his west lay the Karakhitan Empire.
Zhilugu, Gurkhan of the Karakhitans (1178–1211), had preferred to rule peacefully from Balasagun over the central Eurasian steppes, Transoxiana, and Western Tarim Basin, but he faced repeated challenges from his unruly Muslim vassals.46 The ailing Gurkhan himself, who doubled as the Chinese emperor Tianxi of the Western Liao dynasty, was content to draw revenues from his diverse subjects who were taxed and administered by Chinese-trained bureaucrats. The Gurkhan, however, had received the refugee prince Kuchlug years earlier. Kuchlug, the indomitable warrior of the Naimans and implacable foe to the Mongols. Kuchlug had refused to submit to Temujin in 1204. He and his followers had fled west to the court of Gurkhan Zhilugu.47 Kuchlug rose in the Gurkhan’s favor, winning a marriage to a daughter of Zhilugu and conveniently converting from Nestorian Christianity to Buddhism in 1210.48 Kuchlug rallied numerous dissidents and exiles who detested Temujin turned Genghis Khan. He also intrigued with the Gurkhan’s vassal Muhammad Shah of Khwarazm to overthrow his father-in-law, and then to partition the Karakhitan domains with Muhammad Shah.49 In 1211, Muhammad Shah revolted, crushed the Karakhitan army, and secured the cities of Transoxiana (Mawarannahr). Meanwhile, Kuchlug ambushed and captured the Gurkhan while on a hunting expedition.50 Thereafter, Kuchlug ruled through his father-in-law as a figurehead until his death in 1213, whereupon Kuchlug ruled as Gurkhan in his own right.51 Kuchlug willingly signed off on the cities of Transoxiana, because he intended to turn the rest of the Karakhitan state into a base to oppose Genghis Khan. From Balasagun Kuchlug could draw upon the Turkish nomadic horse archers of the central Eurasian steppes and the wealth of the western and southern caravan cities of the Tarim Basin. In effect, he ruled a provincial Chinese bureaucratic state which he hoped would give him the means to confront Genghis Khan. But as a zealous convert to Buddhism, Kuchlug foolishly persecuted his Muslim subjects, even crucifying a defiant iman of Khotan.52
Genghis Khan received many appeals from Uyghurs and Khitans against the tyrant Kuchlug, who, it was feared, was organizing an army to challenge Genghis Khan’s supremacy over Mongolia. In 1218, Genghis Khan decided to act decisively. Jebe, with two crack tumenler (twenty thousand horsemen), invaded the Karakhitan Empire, and the Mongols were hailed as liberators by the outraged Muslim subjects of Kuchlug.53 Jebe took the city of Kashgar by surprise. Kuchlug barely escaped from the city, and fled into the Pamirs. But he was ignominiously recognized and captured by a hunter who turned him over to Jebe. Jebe ordered the Naiman prince beheaded.54 By this single short campaign, Genghis Khan extended his sway over large swaths of the central steppes to the banks of the Jaxartes River (Syr Darya) and the Aral Sea. He now shared a frontier with Muhammad Shah, deeply suspicious of his new neighbor to the northeast.
Muhammad Shah suspected the imperial ambitions of Genghis Khan, and he provoked an incident that resulted in the first Mongol invasion of the Muslim world and the collapse of his own Khwarazmian Empire. In 1215, three Bukharan merchants outfitted a caravan and traveled to Karakorum so that they could present rich gifts to Genghis Khan and then sell luxuries to the Mongol elite at high prices.55 The savvy Persian merchants had received news of Genghis Khan’s capture of Zhongdu and the fabulous wealth in the storerooms of Karakorum. They were well rewarded for their generous gifts and polished ways. Three years later, in 1218, they returned home accompanied by three Mongol envoys who carried a letter from Genghis Khan to Muhammad Shah. Two versions of the letter are reported by Juvayni and Rashid al-Din, respectively. Each version is a polite request for trade, but Juvayni stresses that Genghis Khan addressed Muhammad Shah as an inferior prince.56 Muhammad Shah must have flown into rage over the Mongol khan’s pretensions. At the same time, he feared that Genghis Khan would not be satisfied with his conquests in distant China, but he would look to the west next.
Meanwhile, in the same year, a Mongol caravan arrived at Otrar (or Urtar) on the upper Jaxartes River. The governor Inal Khan, perhaps acting on orders from Muhammad Shah, seized the goods and executed the merchants and an envoy of Genghis Khan on grounds that they were Mongol spies.57 The accusation was plausible, if not true. Genghis Khan immediately demanded compensation. Muhammad Shah refused to pay, and so Genghis Khan promptly declared war. Muhammad Shah has been criticized for foolishly precipitating a war that released a whirlwind of destruction on the Islamic world, but at the time he had a reasonable expectation that he could defend his realm.58 Muhammad Shah has been unfairly portrayed as haughty and incompetent by hostile sources, Mongol and Islamic alike. Yet he viewed the Mongols as barbarians content to loot and leave just like previous nomadic invaders from the steppes.59 Far more important were his plans to conquer the eastern lands of Dar al-Islam and to subordinate the Abbasid Caliph in Baghdad so that he could rule as the legitimate Turkish sultan over Sunni Islam. Muhammad Shah, himself Turkish in origin, employed Persian ministers and promoted the high culture of eastern Islam, but he based his field army on Kipchak and Cuman mercenaries and ghilman, slave soldiers.60 With good cause, Muhammad Shah feared the expansion of Mongol power across the western Eurasian steppes and the loss of access to the recruiting grounds of Kipchak Turks. Furthermore, he had also easily smashed the Karakhitan army so that he dismissed the Mongols as similar pagan barbarians. He had no experience in confronting a Mongol army with a strategic and logistical speed hitherto unknown. Instead, Muhammad Shah shared with his Muslim contemporaries a far greater fear of the Crusading Franks bent on capturing the great cities in the heartland of Islam. In the spring of 1219, members of the Fifth Crusade, who had already captured the port of Damietta, the gateway to Egypt, threatened to advance on Cairo.61 Rumors circulated alleging that the Emperor Frederick II, stupor mundi, was about to arrive with a vast host to command the final advance. Muslims feared Frederick as the greatest of Christian kings, and respected him as a civilized foe fluent in Arabic and conversant in Islamic theology.62 But Frederick proved a no-show. The Crusaders, bogged down in the canals of the Egyptian Delta, stalled, and withdrew in defeat. Frederick’s repeated excuses to postpone his promised crusade earned him the ire and excommunication of Pope Gregory IX.63 Instead, the Mongols unexpectedly burst into the Islamic world from the northeast.
In the spring of 1219, Genghis Khan, at age sixty, had meticulously planned and led his third and by far most audacious offensive campaign. He summoned virtually the entire levy of the Mongol nation as well as Khitan and Uyghur allies, and, of course, his Chinese engineering and medical corps. His army might have totaled as many as one hundred fifty thousand men, and over one million mounts. The expedition posed unprecedented strategic and logistical challenges.64 Well in advance, Genghis Khan ordered the routes across the steppes cleared so that his army could move swiftly over three thousand miles from Karakorum to the grasslands of the Irtysh valley. Each Mongol warrior was accompanied by as many as ten remounts so that fodder and water were essential if the Mongol army were to cover the distance at forty miles per day. Within ten weeks, at the end of the summer, Genghis Khan had reached the Jaxartes River (Syr Darya), to the dismay of Muhammad Shah, who was still mobilizing his ponderous army.
On the Jaxartes River, Genghis Khan boldly divided his smaller army into three strategic columns.65 While Genghis Khan and his youngest son, Tolui, with the main force moved against Bukhara, his other sons commanded the two other columns. His sons Chagatai, the most aggressive, and Ögedei, the most judicious, attacked Otrar on the middle Jaxartes River.66 When the city fell, the Mongols massacred the population. The Khwarazmian governor Inal Khan, who had provoked the war, was cruelly punished. Molten silver was poured down the throat.67 Farther east in Ferghana, the Great Khan’s eldest son, Jochi, besieged and captured Khujand.68 Within months, in early 1220, the Mongols had overrun the northeastern defenses of Muhammad Shah, and so they ravaged at will all of Transoxiana, Afghanistan, and northern Iran. Mongol columns captured every major city on the Silk Road from Samarkand to Tabriz, either by siege or voluntary submission, in less than two years.69 Everywhere the Mongol army was invincible, while Muhammad Shah’s mercenaries and slave soldiers deserted or surrendered after token resistance, only to be promptly massacred by their captors.
From Bukhara, Genghis Khan advanced on Samarkand, and within a month the citizens of this fabled city, celebrated for its lush gardens and fountains, surrendered. Once again, the residents were ordered to evacuate the city. Samarkand was then plundered; the Turkish garrison was slaughtered; thirty thousand artisans and skilled residents were deported to Mongolia.70 The fall of Samarkand, a capital of the Karakhitan and Khwarazmian states, marked the collapse of Muhammad Shah’s realm. Muhammad Shah fled west into Khurasan, but before he could rally his soldiers, Jebe and Sübetei arrived in hot pursuit with two tumenler of twenty thousand men.71 Muhammad Shah narrowly escaped to a small island opposite Abeskun on the southern shores of the Caspian Sea, where he died a broken man by the end of the year. Meanwhile, Jebe and Sübetei relentlessly rode west across northern Iran, invaded Christian Armenia and Georgia, and then crossed the Derbent Pass onto the Pontic-Caspian steppes, where they defeated a joint Cuman-Russian army on the banks of the Kalka River on May 31, 1223.72 Soon after, they rejoined their master in Central Asia, flush with victories and carrying information invaluable for the future conquest of the distant western lands.
Meanwhile, within a year of the surrender of Bukhara, Genghis Khan crossed the Oxus River (Amu Darya). Balkh immediately submitted, but Tolui stormed Merv, and punished the defiant residents, reputedly numbering seven hundred thousand, by ordering their massacre.73 Herat, yet another famed oasis city of the Silk Road in Hari valley, suffered an equally gruesome fate six months later in the autumn of 1221.74 Farther west in Khurasan, Genghis Khan just as ruthlessly punished the rebels of Nishapur, home of the poet Omar Khayyam. Nishapur, which had submitted to Jebe and Sübet the year before, renounced its fealty once the Mongols rode west. Tokuchar, son-in-law of Genghis Khan, fell in a skirmish during an abortive attack by the Mongols to retake the city.75 In April 1221, the Mongols stormed into the city and massacred the population. Muslim chroniclers report grisly scenes of pyramids of human heads; even dogs and cats were slaughtered. Bamyan, however, suffered the most frightening fate of all. There, six centuries earlier the Chinese monk Xuanzang had reverently gazed upward to the two colossal statues of Buddha as Vairocana and Sakyamuni. During the savage fighting in the strategic valley, Mutugen, Genghis Khan’s favorite grandson, was killed by an arrow. The vengeful Great Khan ordered all living creatures in Bamyan slain. The city was leveled to the ground, cursed and forever abandoned.76
In 1221, cities in Afghanistan and Khurasan resisted on the false hopes that Jalal al-Din, the dashing son of Muhammad Shah, would soon arise and smite the barbarians. From the outset, Jalal al-Din had vehemently objected to his father’s strategy of trusting to fortified cities and avoiding battle with the Mongols.77 When Muhammad Shah opted for an obscure exile on the shores of the Caspian Sea, his son rallied forces in Khurasan and fought his way east to Ghazna, where he summoned reinforcements from his vassals in northern India.78 Genghis Khan, however, once again outmaneuvered his Khwarazmian foe, surprising Jalal al-Din before he could marshal his forces. In November 1221, Jalal al-Din retreated across the Hindu Kush. Genghis Khan followed. On the banks of the middle Indus north of Multan, Genghis Khan smashed the motley forces of Jalal al-Din, who only avoided capture by swimming across the Indus. Genghis Khan chose not to pursue the fugitive prince without a kingdom into India, and he retired to the winter pastures just south of the Hindu Kush.79
In the next year, 1222, Genghis Khan shifted from conquest to consolidation. Over the next eighteen months, he toured the cities of Khurasan and Transoxiana. Just as in China, Genghis Khan understood that he could only administer these new provinces by co-opting Persian officials and imans, and by recognizing the legal status of Islam.80 He had little time to perfect a new central administration for the lands of eastern Islam, because he was pressed to return to Mongolia. When he finally reached Karakorum in 1225, eight years had passed since his departure. He still had to reckon with the Jin emperor in Kaifeng, and the new emperor of the Xi Xia Aizong who repudiated his Mongol alliance.81 Before Genghis Khan could complete his campaign against the Xi Xia, he died in August 1227, at the age of sixty-five.
The Khwarazmian campaign of Genghis Khan had changed the world. To the shock of the Islamic world, Genghis Khan and his Mongols, unexpectedly and swiftly, captured and sacked the great cities of Eastern Islam. Some of the caravan cities, such as Bamyan and Urgench, never recovered and lie in ruins to this day. Prosperity returned to the other cities of the Silk Road during the next two generations under Mongol peace imposed by Great Khan Ögedei, and then by Hulagu and his heirs, who ruled as the Ilkhans of Iran.82 The sudden collapse of the Khwarazmian Empire struck terror in the hearts of Muslims who saw the new invaders as the sons of Gog and Magog come to announce the end of the world as foretold in the Koran. Muslim rulers were stunned and uncertain how to act.83 Imans fervently urged true believers to return to the moral strictures of the Koran lest they risk a catastrophic end of days wrought by these unclean peoples of the steppes. Genghis Khan also triggered a major migration west within the Islamic world that redrew linguistic and religious boundaries that still determine the Middle East today. Genghis Khan unintentionally hastened the shift of the central steppes and Transoxiana, today represented by the nation states of Kazakhstan, Kyrgyzstan, Turkmenistan, and Uzbekistan, from Iranian-to Turkish-speaking lands.84 Numerous Persian refugees fled the great cities of Transoxiana and Khurasan west to Syria and Anatolia.85 Among them was the family of Bahā ud-Dīn Walad, a jurist and mystic of Balkh, who ultimately settled in Konya, capital of the Seljuk sultanate of Rum.86 His son, Jalāl ad-Dīn Mohammad Rūmī, who succeeded to the family medresse, turned out to be the Mevlana. The Mevlana, inspired poet and founder of the Mevlevi order of Whirling Dervishes, initiated the conversion of Byzantine Christian Anatolia into Muslim Turkey. Many Turkish tribes too fled west into Anatolia. Among them was an obscure tribe dwelling near Merv who were reputedly the ancestors of the Ottomans.87
Meanwhile, in Acre, on the distant shores of the Levant, Bishop Jacques de Vitry hailed garbled reports about Genghis Khan’s victories as proof that David, the son, or perhaps the grandson, of Prester John, was on the march with a great host to join members of the Fifth Crusade and smite the Muslims.88 Disquieting reports arrived soon after about the Mongols wreaking havoc in Christian Georgia and Armenia, and then defeating the Russian princes.89 But these reports were dismissed as God’s punishment of George IV for his failure to come to the aid of the Crusaders, and the Orthodox Russian princes, who were, after all, obdurate schismatics refusing to acknowledge the spiritual authority of the Pope. Latin Christendom instead eagerly anticipated the imminent arrival of the Mongols as the warriors of Prester John. But their hopeful expectations turned to shock and horror dashed twenty years later when the Mongols invaded Central Europe.
Before embarking on his Khwarazmian campaign, the Secret History reports a tempestuous meeting between Genghis Khan and his four sons over the succession.90 Jochi, encouraged by his father, claimed the right to speak first, but he was immediately challenged by Chagatai, who cast aspersions on his brother’s paternity. Ögedei, always the favorite and slightly inebriated as usual, urged reconciliation. The youngest son, Tolui, remained inconspicuously in the background. Genghis Khan, saddened and dismayed, had to implore his sons to stand together for the sake of the Mongol nation. He nominated Ögedei to succeed as Great Khan. In contrast, the two Persian chroniclers Juvayni and Rashid al-Din each reports dignified, sober deliberations on the matter, but they are unclear as to the precise date of these discussions.91 Most likely, Genghis Khan, when he prepared for his Khwarazmian campaign, raised the issue of succession lest his sons quarrel should he fall in the forthcoming campaign.
The fighting in Khwarazm soon confirmed in Genghis Khan’s mind that Ögedei should succeed as the Great Khan. While Genghis Khan and his youngest son, Tolui, with the main army overran Transoxiana, Afghanistan, and Khurasan, Genghis Khan ordered his three older sons, Jochi, Chagatai, and Ögedei, to unite their armies and to besiege Urgench, the principal city of Khwarazm, which lay at the mouth of the Jaxartes River as it emptied into the Aral Sea.92 Urgench (also known as Gurganj), renowned for its silks, was a favorite residence of Muhammad Shah. The garrison heroically defended Urgench for seven months, between October 1220 and April 1221. Jochi and Chagatai repeatedly quarreled over operations and the ultimate fate of the city so that Genghis Khan finally had to appoint Ögedei as supreme commander.93 Jochi, who was promised the city, wanted to capture Urgench intact, and thus profit off its silk plantations, whereas Chagatai delighted in pressing the siege at all costs and punishing the city as a deliberate act of terror, and to the annoyance of his brother Jochi. Ultimately, Chagatai prevailed. During the siege, the Mongols chopped down the groves of mulberry trees, the source of nourishment for the silkworms, to construct siege engines. Finally, Ögedei diverted the Syr Darya to undermine the walls. When the Mongols burst in the city, they massacred the population. Many Mongols took sadistic pleasure by disemboweling citizens suspected of having swallowed their jewelry or pearls.94 The city was abandoned, and the diverted Syr Darya flowed into the Caspian Sea for the next three hundred years until the course shifted again to the Aral Sea. The city never recovered; today the site is ruins. A successor city was built on a different site but this city too was abandoned when the river again changed course in the time of Tamerlane.95
When Genghis Khan returned to his capital Karakorum in 1225 he must have sensed his mortality and so he urged his sons to accept as Great Khan their brother Ögedei, who was the third son of Genghis Khan and Börte. The eldest brother, Jochi, for all his loyalty, could never wash away the taint of a dubious parentage. To Jochi, Genghis Khan promised the western steppes still to be conquered and destined to be called the Golden Horde. Jochi’s son Batu succeeded to this realm because Jochi predeceased his father by a matter of months.96 Second son Chagatai, notorious for his hot temper, received the central Eurasian steppes, along with the cities of the Tarim Basin and Transoxiana. He and Ögedei remained on good terms, and they died within weeks of each other. To Tolui, the youngest, went Mongolia and the sacred Orkhon valley, seat of the national kurultai.97 Genghis Khan reasoned that under the amiable Ögedei the brothers, each provided with ulus or a nation of warriors, would cooperate and press his vision of world conquest. Genghis Khan would not have been disappointed, for he had chosen well.