Genghis Khan was born as Temujin, in the 1160s, in the area of modern day Mongolia. By 1190, he and his followers had united many of the nomadic tribes of northeast Asia, creating a Mongol confederation. They went on to forge a great Mongol Empire, leading invasions across most of Eurasia. Under Temujin’s leadership, the Mongol Empire conquered and/or incorporated the Keraits, Naimans, Merkits, Tanguts, Jin and Tatars. At a council of Mongol chiefs, he was acknowledged as Khan of the consolidated tribes and took the new title, "Genghis Khan."
Temujin had been promised in an arranged marriage at the age of nine. The marriage took place when he was 16. The couple had four sons, who took on the mantle of power after their father’s death. Later, when he rose to power, Temujin took several other wives and had many children, but all were excluded from succession.
By the time he died in 1227, the Mongol Empire occupied much of Central Asia and China. He left behind an army of more than 129,000 men. His sons and grandsons extended his empire across most of Eurasia, conquering or subduing the territories of modern-day China, Korea, the Caucasus, and Central Asia, and much of Eastern Europe, Russia and the Middle East. Invasions under Genghis Khan and his sons were often accompanied by the wholesale slaughter of local populations. Historians suggest that Mongol invasions may have resulted in the deaths of up to 40 million people.