In the year 1206, a central Asian nomad called Temujin used his political savvy and charm to unite previously feuding tribes and found the largest empire that has ever existed.
He was proclaimed universal leader and his exploits as the all-conquering warrior of the great Mongol empire - which at its height in the 13th and 14th centuries stretched from the Pacific Ocean to Europe - have resonated through the centuries. His name, of course, was Genghis Khan.
When a group of geneticists concluded three years ago that 16 million men across Eurasia shared such a curious family tree they must all be descended from the same ancestor, and that, incredibly, Genghis Khan fitted the bill, it only added to the myth of the testosterone-fuelled warmonger.
But now a new exhibition marking the 800th anniversary of the foundation of the Mongol empire wants to challenge popular perceptions of the man who did it.
Genghis Khan and his Heirs: the Great Mongol Empire, which opened in Istanbul yesterday, suggests the warrior chief's reputation as a bloodthirsty warrior has been warped. Instead, it hails him as a tolerant, meritocratic law-giver whose reign - and that of his many descendants - led to the profitable flourishing of commerce and ideas from the Mediterranean to China for 200 years. Though no surprise to the Mongolians, who have long revered Genghis as thefather of their nation, the show looks like quite a makeover.
Opening the exhibition at the Sakip Sabanci Museum, its director, Nazan Olcer, said Genghis Khan's major achievement was the creation of the so-called Pax Mongolica which offered security to the entire region and enabled travellers such as Marco Polo to move freely along the Silk Road.
"This great come-and-go meant an immense commercial and artistic exchange between the West and the East," she said. "That was his long-lasting legacy."
For a man once voted one of the most important political leaders of all time by National Geographic, and man of the millennium by The Washington Post, the blanks in his known history are numerous.
Even the face peering out from giant posters across Istanbul is a 14th-century depiction. And the primary source for the biography of Genghis Khan is The Secret History of the Mongols, written in China after his death.
What is accepted is that Temujin was born around 1162 to an impoverished family of nomads. He was married at around the age of 16 to Borte, and pledged his allegiance to Toghrul, a close ally of his father who was the leader of the Keraits. When his wife was kidnapped by the Merkits he raised an army to get her back, and succeeded. Further conquests followed until he had united the Merkits, Naimans, Mongols, Uighurs, Tatars and other previously warring tribes under his rule, an unprecedented achievement.
In 1206 he was acknowledged the leader of the tribes, and within a century the Mongol empire had extended across the steppe lands of Iran and Russia to the plains of Hungary - provoking panic across Europe.
"Last year a people invaded the Ruthenian empire and destroyed an entire clan," wrote Caesarius von Heisterbaen in Germany in 1222. "We do not know who they are, where they came from and where they are going."
Genghis Khan and his heirs brooked no resistance. When Pope Innocent IV wrote in 1245 asking Genghis's son Ogedei, known as the Great Khan, to stop slaughtering people, especially Christians, the response was a scarcely disguised threat to Christendom to submit, or else.
But although he could be brutal, Genghis Khan was meritocratic compared with earlier tribal chiefs. His sons, who continued his work in China - under the fabled Kubla Khan - Persia and Russia, allowed indigenous culture to remain, so that Mongol influence can be hard to discern.
Dr Susanne Wichert-Meissner, of the Art and Exhibition Hall in Bonn - which has previously hosted the exhibition - said: "The conquered people were not forced to adopt a foreign culture, as Genghis Khan chose to use their diverse skills and cultures to his own benefit."
The Mongols remained nomadic, and Khan did not establish a city base until 1220, when the need for an administrative centre to support his mission prompted the founding of Karakorum - where German, French and Turkish archaeologists are now digging up new information.
But gaps in our understanding remain. Genghis Khan died on a military campaign in 1227, but the site of his burial remains unknown. "He built an empire like no other in history, the largest in the world," Dr Wichert-Meissner said. "He's one of the most famous personalities in history, but he didn't leave palaces or a magnificent grave behind."Reuse content