The old Mohammedan authors, such as Massoudi and Ebn Haoucal, who treat of the nations of Asia, appear not to have known the Tatars, for they never speak of them. Their name figures, however, in a Persian abridgment of universal history, entitled "Modjmel ut Tevarikh el Coussas;" and Reschyd el Dyn calls the Tatars a people famous throughout the world; but it would be difficult to extract from these authorities any precise argument for the solution of our problem. After all, as previously to the days of Genghis Khan, the most important tribe of Mongols bore the name of Tatars, it is not surprising that the Mussulman writers included the whole of that people under this denomination. The Chinese, on the contrary, being in close intercourse with the Tatars, their vassals, must of course have known their generic name, and transmitted it to us.
Now let us recapitulate. If we reflect that Genghis Khan, though born in the tribe especially designated as black Tatars, yet adopted the denomination of Mongols for his people; that historians have been unanimous in calling Genghis Khan's soldiers Mongols; that the Chinese chroniclers, De Guignes, and many others, have considered the Tatars as only a branch of the Mongols; that Du Plan de Carpin himself begins his history with these words: "Incipit historia Mongalorum quos nos Tartaros appellamus," it will not be easy to deny, that previously to the twelfth century, previously to the great Asiatic invasions, the Tatars and Mongols were parts of one nation, belonging to one race. If subsequently the hordes of Genghis renounced their special name, this circumstance must be ascribed to the sanguinary contest which Jessoukai and his son, Genghis Khan, had to sustain against their oppressors, the white Tatars, then the principal tribe in those regions. But the term Tatar still prevailed in Europe, though it continued to be regarded as synonymous with Mongol by all the Chinese writers, and by most of those of other nations.
The religious and political constitution of the various Mongol or Tatar branches before Genghis Khan, is very imperfectly known to us, and affords us no manner of ground for presuming a positive separation into two races. According to the Mongol work, "The Source of the Heart," written in the beginning of the thirteenth century it appears that Lamism was first adopted by Genghis Khan, and that it became under his successors the prevailing religion of the Mongols proper. Marco Polo's narrative seems nevertheless to prove, that at the end of the thirteenth century the Mongols had not yet entirely adopted the creed and rites of Lamism; we now find it professed by all the Kalmucks of Russia.
In later times, after the invasions by Genghis Khan and his sons, the Europeans, through ignorance or heedlessness, gave the name of Tatars not only to the tribes who had figured in those Asiatic irruptions, but also to the Mahometans, who had once been masters of the regions adjacent to the Caspian and the Black Sea, and had been subjugated by those conquerors; hence have arisen in a great measure all the mistakes and discussions respecting the origin of the Tatars. After the Mongol torrent had subsided, Europeans persisted in giving the appellation of Tatars to all those Mussulman nations originally of Turkish origin, that to this day occupy the territory of Kasan and Astrakhan, the Crimea and the region called Turcomania, situated between the Belur Mountains, Lake Aral, and the Caspian Sea; and as all these nations exhibited a religious, political, and moral character peculiar to themselves, people were naturally led to distinguish them from the Mongols, and to attribute to them a special origin. Thus Pallas and many other travellers, after visiting the Mahometans of Southern Russia, and comparing them with the Kalmucks, have made of the Tatars and Mongols two distinct races; and Malte Brun, in his geography, has given the name of Tatar to all the tribes established in our day in Turkistan, applying that of Mongol exclusively to the nations inhabiting the central tableland of Asia, from Lake Palcati and the Belur Mountains to the great wall of China, and to the Siolky Mountains which separate them from the Manchous, a tribe of the great race of the Tongouses. All these writers have failed to observe, that the appellation Tatar lost all signification in Asia under the destroying power of Genghis Khan, and has ever since existed only in the European vocabulary.
Doubtless, Genghis Khan and his successors did not achieve all their conquests by the arms of the Mongols alone; and after having subjugated all the Mahometan nations occupying the vast regions of Turcomania and a part of Western Asia, they of course incorporated them with their hordes, and employed them in their European invasions.