Modern Mongols have a classic East Asian appearance, assuming dark hair, a specific skull shape, characteristic eyes and specific body proportions different from European ones. Due to their military successes during the High Middle Ages, such a racial type was named Mongoloid.
However, there are opinions from various sources that even a thousand or more years ago the ancestors of this people had a different appearance. And the Mongols themselves seem to share the idea that their historical predecessors were two-meter blond-haired handsome men looked different.
The ancestors of the Mongols first entered the historical arena in the 1st century AD under the name of Xianbi. At that time they were vassals of the Huns, who together with them tormented China with their raids. The type of appearance of their suzerains at that time depended strongly on their social status — the more noble a person was, the more East Asian his appearance was. Whereas the racial type of the ancient Mongols at that time was not determined by their status.
The Chinese were somewhat surprised by their appearance, describing these nomads as a “white” people. According to many descriptions, they had fair skin, red hair and blue eyes. The shape of the eyes was not specified, apparently it was not surprising. In 324th year the son of Xianbi princess Emperor Ming-di from the state of East Jin fought with rebels. Those were confused by his appearance and thought he was a Xianbi because of his red hair and beard.
However, we do not know exactly what color is meant by the Chinese character for “yellow” and “yellow-headed,” which is used to describe members of this tribe. Perhaps red, russet, brown or other hair color was meant. In any case, even a slightly lighter tone than the darker Chinese was perceived by the Celestial people as unusual. Even today, the Chinese, Koreans and Japanese perceive Mongols as light-colored people compared to themselves. Europeans could have the opposite opinion on this matter, but everything is known in comparison.
Even before the era of conquest, some representatives of Mongolian tribes looked somewhat different from other East Asians. Thus, the khans Yesugei, Temujin and Ugedei are described as red-haired men. The Chinese also noticed that, unlike the inhabitants of their own country, Mongols could have different colored eyes.
The more varied appearance than other neighbors is due to the fact that 10-15% of Mongolian genes come from European and West Asian populations, including the Caucasoid race. They were derived from three main sources: the first were the Paleo-Siberians, who were somewhat mixed with Europeans; the second were the Indo-Europeans, especially the Eastern Scythians, who were assimilated by the Hunnu and the Mongols themselves; the third were those peoples of Central Asia with whom the Mongols mixed during their world conquests.
Since the latter were carried on eight centuries ago, it is assumed that the ancient Mongols were more East Asian than the modern ones. It is true that until late antiquity and the early Middle Ages, Asia, up to what is now Western China, was inhabited by Eastern Scythian and Indo-European populations. And only the migrations and wars of the last 1-1,5 thousand years changed everything. Therefore, the ancient Mongols could be much lighter in color.
However, their modern descendants come from different tribes. And, unlike China, Japan and Korea, there is no homogeneity among the locals. Mongols usually easily distinguish their own, and do it by higher cheekbones; reddish, but pale, especially in youth, skin; stronger physique; lighter tones of eyes and hair.
A great many Mongols have light brown hair, which looks almost like blond in childhood and youth. Gray and greenish eyes are not so rare here.