In Temujin’s youth, his father had built a modest tribal following. When Temujin’s father was poisoned by a rival, his followers drifted away, leaving Temujin and his mother and brothers in a vulnerable position. Temujin slowly collected followers. In 1182 Temujin was captured and carried in a cage to a rival’s camp. After a daring escape, he led his followers to join a stronger chieftain whom his father had once aided. With the chieftain’s help, Temujin began avenging the insults he had received.

Temujin proved to be a natural leader, and as he subdued other nomadic tribes, he built up an army of loyal followers. He mastered the art of winning allies through displays of personal courage in battle and generosity to his followers. To those who opposed him, he could be merciless. He once asserted that nothing gave more pleasure than massacring one’s enemies, seizing their horses and cattle, and ravishing their women.

In 1206, at a great gathering of tribal leaders, Temujin was proclaimed Chinggis Khan, or Great Ruler. Chinggis decreed that Mongol, until then an unwritten language, be written down in the script used by the Uighur Turks. With this script a record was made of the Mongol laws and customs. Another measure adopted at this assembly was a postal relay system to send messages rapidly by mounted courier, suggesting that Chinggis already had ambitions to rule a vast empire.

With the tribes of Mongolia united, the energies previously devoted to infighting and vendettas were redirected to exacting tribute from the settled populations nearby, starting with the Jurchen (Jin) state that extended into north China. Because of his early experiences with intertribal feuding, Chinggis mistrusted traditional tribal loyalties, and as he fashioned a new army, he gave it a new, nontribal structure. He conscripted soldiers from all the tribes and assigned them to units that were composed of members from different tribes. He selected commanders for each unit whom he could remove at will, although he allowed commanders to pass their posts on to their sons.

After Chinggis subjugated a city, he would send envoys to cities farther out to demand submission and threaten destruction. Those who opened their city gates and submitted without fighting could join the Mongols, but those who resisted faced the prospect of mass slaughter. Not surprisingly many governors of cities and rulers of small states hastened to offer submission.

Chinggis preferred conquest to administration and did not stay in north China to set up an administrative structure. He left that to subordinates and turned his attention westward, to Central Asia and Persia, then dominated by different groups of Turks. In 1218 Chinggis proposed to the Khwarizm shah of Persia that he accept Mongol overlordship and establish trade relations. The shah ordered the envoy and the merchants who had accompanied him killed. The next year Chinggis led an army of one hundred thousand soldiers west to retaliate. Mongol forces destroyed the shah’s army and sacked one Persian city after another.

After returning from Central Asia, Chinggis died in 1227 during the siege of a city in northwest China. Before he died, he instructed his sons not to fall out among themselves but instead to divide the spoils.