History's greatest conqueror emerged from obscurity in 12th-century Mongolia, when the steppes north of the Great Wall of China were occupied by tribes and clans entangled in constantly shifting alliances, rivalries and disputes. Fierce warriors, the Mongols claimed to be descended from the Huns (Hun being the Mongol word for human being). The Jurcheds, who ruled northern China and Manchuria, deliberately fomented quarrels among the Mongols and the other tribes north of the Great Wall to stop them from being a nuisance.
A boy called Temujin was born around 1162 to Yesugei, the khan or leader of a minor Mongol clan, the Borijin. The name Temujin seems to have come from a Mongol word meaning 'headstrong' and 'inspired' and it suited him and perhaps helped to inspire him. His father, Yesugei, was poisoned when Temujin was still a boy. Temujin developed into an overwhelmingly commanding personality with a genius for warfare, which he employed to bring the other Mongol groups under his control. Starting by stalking and killing his elder half-brother, he took command of his clan and went on over many years to kill leading figures in rival groups and threaten or win others into his service. By his mid-forties in 1206 he was acknowledged by the admiring peoples of the steppes as Genghis Khan (Chinggis Khan, or 'unshakeable ruler').
In 1210 envoys from the Jurched capital of Zhongdu (later Peking and now Beijing) arrived in Mongolia announcing the accession of a new Golden Khan, as their ruler was called, and demanding that Genghis Khan and the Mongols formally accept his suzerainty. Genghis spat contemptuously on the ground, treated the envoys to a volley of insults at the Golden Khan and rode away. He summoned a meeting of his tribespeople – men, women and children – to consider the situation. Once he felt certain they were with him, he went up to the top of a nearby mountain where he bowed down to the Eternal Blue Sky and informed it that he and his people had not looked to fight the Jurcheds, but were being forced into war by them. On the fourth day he came down and told the people what he had done and that the Eternal Sky had promised them victory and revenge.
Secure in his people's support, Genghis led a succession of campaigns. Mongol armies travelled and fought on horseback and took huge numbers of reserve horses with them. They had no supply train to delay them, could survive on little food and lived off the land, pillaging as they went and eating some of their horses if they needed to.
In his Genghis Khan and the Making of the Modern World (2004) Jack Weatherford said that Genghis Khan 'had lit a conflagration that would eventually consume the world'. After repeated campaigns, by 1213 the Mongols had overrun all the Jurched territory north of the Great Wall. Genghis Khan now broke through the Wall and attacked northern China, which his forces ravaged and plundered. In the spring of 1214 they descended on the Jurched capital at Zongdhu. There had been a coup there and the newly installed Golden Khan did not feel secure enough to face a prolonged siege. He offered substantial rewards if the Mongols would withdraw, including enormous quantities of gold, silver and silk, as well as thousands of horses. He gave Genghis Khan a Jurched princess as a wife and acknowledged the Mongol chieftain as his overlord.
Satisfied, Genghis Khan left to return to Mongolia, leaving the Jurched regime to continue in China and pay him tribute as their overlord, but the Golden Khan soon broke the agreement. He aband-oned Zhongdu and moved his court to the city of Kaifeng, far to the south. Genghis Khan was infuriated at what he considered a betrayal. In 1215 he marched back to Zhongdu. Many of its people also felt betrayed by the Golden Khan and the Mongol siege starved the city into submission. Genghis Khan went back to Mongolia, leaving his subordinates to sack Zhongdu, which they did with enthusiastic thoroughness and zeal.
In his last years Genghis Khan extended his sway over northern China, invaded Afghanistan and pressed on into Georgia, Russia and northern Persia. Cities were taken and populations ruthlessly massacred. When Genghis Khan died in his sixties in 1227, of fever after a bad fall from his horse, his empire stretched from the Pacific to the Black Sea and covered an area larger than the Roman Empire at its height. His descendants would make it bigger still
