Genghis Khan (1167-1227) was the creator of the Mongol nation and the founder of one of the vastest empires the world has ever seen.
Genghis Khan, whose original name was Temüjin, was born on the banks of the river Onon in the extreme northeast corner of present-day Mongolia. He was left an orphan at the age of 9, his father, a nephew of the last khan of the Mongols, having met his death at the hands of the Tatars, who in the second half of the 12th century had displaced the Mongols as the dominant tribe in eastern Mongolia. Temüjin's mother was deserted by her husband's followers at the instigation of the Taichi'uts, a rival clan who wished to prevent his succeeding to his father's position, and she was reduced to bringing up her family in conditions of great hardship.
When Temüjin had grown into young manhood, he was taken prisoner by the Taichi'uts, whose intention it was to keep him in perpetual captivity. However, he succeeded in escaping and soon afterward became the protégéof Toghril, the ruler of the Kereits, a Christian tribe in central Mongolia. It was with the aid of Toghril and a young Mongol chieftain called Jamuka that Temüjin was able to rescue his newly married wife, who had been carried off by the Merkits, a forest tribe in the region which is now the Buryatiya in present-day Russia. For a time after this joint operation Temüjin and Jamuka remained friends, but then, for some obscure reason, a rift developed between them and they parted company. It was at this time that certain of the Mongol princes acclaimed Temüjin as their ruler, bestowing upon him the title by which he is known in history, Chingiz-Khan (Genghis Khan), which bears some such meaning as "Universal Monarch."
Genghis Khan's patron Toghril was driven into exile and then restored to the throne by the efforts of his protégé2 years later, in 1198, the first precise date in Genghis Khan's career. The two chieftains allied themselves with the Chin rulers of North China in a campaign against the Tatars, Toghril being rewarded for his share in the joint victory with the Chinese title of wang (prince), whence his Mongol title of Ong-Khan, while Genghis Khan received a much inferior title. In 1199 they took the field against the Naimans, the most powerful tribe in western Mongolia, but the campaign was unsuccessful owing to Ong-Khan's pusillanimous conduct. In the years 1200-1202 the allies won several victories over a confederation of tribes led by Genghis Khan's former friend Jamuka; and in 1202 Genghis Khan made his final reckoning with the Tatars in a campaign which resulted in their total extinction as a people.
Relations with Ong-Khan had in the meanwhile so deteriorated that it came to open warfare. The first battle, though represented as indecisive, seems in fact to have been a defeat for Genghis Khan, who withdrew into a remote area of northeastern Mongolia. He soon rallied, however, and in a second battle (1203) gained a complete victory over Ong-Khan, who fled to the west to meet his death at the hands of the Naimans, while his people, the Kereits, lost their identity, being forcibly absorbed by the Mongols.
Genghis Khan now turned against his enemies in western Mongolia: the Naimans allied with Jamuka and the remnants of the Merkits. The Naimans were finally defeated in 1204, and Küchlüg, the son of their ruler, fled westward to find refuge with the Kara-Khitai, descendants of the Chinese Liao dynasty, who after their expulsion by the Chin had founded a new empire in the area of present-day south Kazakhstan and Xinjiang region of China. Jamuka, now a fugitive, was betrayed by his followers and was put to death by Genghis Khan, his former friend, who found himself at last in undisputed control of Mongolia. In 1206 a kuriltai, or diet, of the Mongol princes, meeting near the sources of the Onon, proclaimed him supreme ruler of the Mongol peoples, and he was now able to contemplate the conquest of foreign nations.
Already, in 1205, Genghis Khan had attacked the Tanguts, a people of Tibetan origin in what is today Kansu and the Ordos Region of China, and two further campaigns against that people in 1207 and 1209 cleared the way for a frontal assault on China proper. In 1211 the Mongols invaded and overran the whole of the region north of the Great Wall; in 1213 the wall was breached, and their forces spread out over the North China plain; in the summer of 1215 Peking was captured and sacked, and the Chin emperor fled to Kaifeng on the southern banks of the Yellow River. Leaving one of his generals in charge of further operations in North China, Genghis Khan returned to Mongolia to devote his attention to events in central Asia.
Küchlüg the Naiman, who had taken refuge among the Kara-Khitai, had dethroned the ruler of that people and had possessed that kingdom. An army dispatched by Genghis Khan chased him from Kashghar across the Pamirs into Afghanistan, where Küchlüg was captured and put to death; and the acquisition of his territory gave the Mongols a common frontier with Sultan Muhammad, the hereditary ruler of Khiva, who as the result of recent conquests had annexed the whole of central Asia as well as Afghanistan and the greater part of Persia.
War between the two empires was probably inevitable; it was precipitated by the execution of Genghis Khan's ambassadors and a group of merchants accompanying them at the frontier town of Otrar on the Syr Darya. Genghis Khan set out from Mongolia in the spring of 1219; he had reached Otrar by the autumn and, leaving a detachment to lay siege to it, advanced on Bukhara, which fell in March 1220, and on Samarkand, which capitulated a month later, the victors of Otrar having taken part in the siege. From Samarkand, Genghis Khan sent his two best generals in pursuit of Sultan Muhammad, who crisscrossed Persia in flight until he met his end on an island in the Caspian Sea. Continuing their westward sweep, the generals crossed the Caucasus and defeated an army of Russians and Kipchak Turks in the Crimea before returning along the northern shores of the Caspian to rejoin their master on his homeward journey. Genghis Khan, in the meantime, having passed the summer of 1220 in the mountains south of Samarkand, attacked and captured Termez in the autumn and spent the winter of 1220/1221 in operations in what is now Tajikistan.
Early in 1221 he crossed the Oxus to destroy the ancient city of Balkh, then part of the Persian province of Khurasan, and dispatched his youngest son, Tolui (Tulë), the father of the Great Khans Mangu (Möngkë) and Kublai, to complete the subjugation of that province, which he subjected to such devastation that it has not fully recovered to this day. In the late summer Genghis Khan advanced southward through Afghanistan to attack Sultan Jalal al-Din, the son of Sultan Muhammad, who at Parvan near Kabul had inflicted a defeat upon a Mongol army. He gave battle to Jalal al-Din on the banks of the Indus; the sultan was decisively defeated and escaped captured only by swimming across the river.
With Jalal al-Din's defeat the campaign in the west was virtually concluded, and Genghis Khan returned by slow stages to Mongolia, which he did not reach till the spring of 1225. In the autumn of the following year he was again at war with the Tanguts; he died, while the campaign was still in progress, in the Liupan Mountains in Kansu on Aug. 25, 1227.
René Grousset, The Conqueror of the World (1944; trans. 1967), is still the best biography, though clearly no longer abreast of contemporary research. Other biographies include Henry Desmond Martin, The Rise of Chingis Khan and His Conquest of North China (1950), and Franklin MacKenzie, The Ocean and the Steppe: The Life and Times of the Mongol Conqueror Genghis Khan, 1155-1227 (1963). Several original sources are available in English translation; the work of the Persian historian Juvaini is available as The History of the World-Conqueror (trans. 1958), and extracts of the native chronicle, The Secret History of the Mongols, are in Arthur Waley, The Secret History of the Mongols and Other Pieces (1963). For details of the campaigns in central Asia and eastern Persia see Wilhelm Barthold, Turkestan down to the Mongol Invasion (trans. 1928), and John Andrew Boyle, ed., Cambridge History of Iran, vol. 5 (1968).