The widely circulated speculation is that Genghis Khan or Chinggis Khaan of Monolia had blue eyes and sandy hair. It all started with accounts of famous XIV-XV century historian Rashid ad Din and Abhu l Ghazi who claim that Genghis Khan and Genghisids had blue green eye and sandy hair and according to them some even had red beards.
Rashid ad Din even goes on to claim that Genghisids were surprised when Great Khan Khubilai, who formed the Yuan Dinasty in China, was born with brown eye, which makes his account more convincing.
During the Yuan Dinasty period itself the Mongols had a formal hierarchy of the people of the Empire consisting of 4 layers: First, Mongols, second, “colored eyed people” who were muslim residents of Yuan Dinasty (it is not clear whether “colored eye” meant blue, green or yellow eyes or just meant people with big eyes. It is highly likely that it meant big eyes, because muslim merchants who lived in Yuan Dinasty were mainly Arabs, Persians and Uighurs), third, the Koreans and Fourth the Chinese.
But, contemporary drawings which are said to be authentic and from Taiwan museum depicts him with strong Orieantal feature and with brown eyes.
Is it possible that the Mongols of that time looked different than Mongols of today? Because there are accounts that Mongol General Subutai or Subedei had sandy or blonde hair. And Soviet expedition who dug the tomb of Tamerlane or Timur Khan, the founder of Mogul Empire, claimed he had strong Europoid features and Red hair.
It seems that Mongols of that time, at least the Mongol soldiers, had the same look as of today’s Mongols.
Valuable historical account of Russia, the Novgorod Chronicle, clearly states that Mongols had black eye and black hair. And it might be explained that Soviet Russian scientist may have mislead the people for whatever reasons. And somehow the account of Genghis Khan and Genghisids having blue green eye and sandy hair is false.
But, there are arguments which may support the claim that Genghis Khan, Genghisids had nordic features such as blue green eyes and blonde hair.
It is known to scientists that remains of Europoid people, the Scythians, are found in Mongolia in west of Khangai Mountains and some scientists even claim that Scythians had been majority until being overrun by Huns.
Only mention about Genghis Khan appearence in “Secret History of Mongols”, written in 12th century is: “fire was burning in his eyes”.
Also, Chinese sources of ancient times claim that, for example, Kirgizs had red hair and blue eyes.
And, albeit few, there are still people in Mongolia who have nordic features in Northern and Western parts of Mongolia.
The strongest support of the authenticity of the claim of Rashid Ad Din that Genghisids had strong nordic features is British Musem portrait of Ugudei Khaan or Ogedei Khan. In it although having typical strong Mongoloid features he has bright green eyes and reddish beard and a fair skin.
And in “Secret History of Mongols”, there is a passage that says that foremother of Genghis Khan, the Alun Goa, had been impregnated by Yellow dogs and gave birth to children when she was a widow. The yellow dogs is suspected by their children to be a slave from Bayud tribe.
So, what are the reasons of Genghis Khan becoming blue green eyes and blondish hair?
Maybe his ancestors came from a place that had Euopean like nordic microclimate, the Sayan mountain range in modern day Tuva or from Western Baikal or Tungusic area. Contemporary Buriyat elders claim that Buriyats of Tungusic origin have green eyes.
Maybe the climate of that time had been quite different than of now and there were plenty of people with strong Nordic features.