Who were the Tatars?

The state of the Tatars emerged in 603 A.H., 1206 A.D., first in Mongolia, in northern China, and its first leader was Genghis Khan (standing for the Conqueror of the world, or the king of the world’s kings, or the most powerful, according to the different translations from the Mongolian language). However, his birth name is Borjigin Temüjin. He was indeed a great slayer and a very strong military leader, and he had the power to gather the people around him. He started to expand his sovereignty gradually in the surrounding territories, and very soon, his state extended from Korea in the east to the borders of the Islamic Khwarezmid State in the west, and from the valleys of Siberia in the north to the Chinese Sea in the south. In other words, it included such countries as China, Mongolia, Korea, Vietnam, Thailand, parts of Siberia, and the kingdoms of Laos, Myanmar, Nepal and Bhutan.
The Tatars or Mongols included the peoples who came from the north of China, i.e. the desert of Juba, even though the Tatars were the origin of all the tribes in this region. From the Tatars, many tribes came, like the Mongols, the Turks, the Seljuks, and others. But when the Mongols, to whom Genghis Khan belonged, took control of the region, all the tribes then were given the name of the Mongols.
The Tatars had an eccentric religion, i.e. a mixture of many religions, in which Genghis Khan collected some laws from Islam, some from Christianity, some from Buddhism, and some from his own self, and ultimately brought out to them a book, which he made a constitution for the Tatars, called Yasak, Yasah or Yasaq.

The wars of the Tatars had the following characteristics:
1- Very rapid spread.
2- Elaborate system and great order.
3- Huge numbers of people.
4- Endurance of hard conditions.
5- Excellent military leadership.
6- They were so heartless that their wars were unnaturally destructive. It is very common to read in their history that they invaded such-and-such a city, destroyed everything in it, and massacred all its inhabitants, making no difference between a man and a woman, an infant, a youth, young and old, wrongdoer and wronged, and civilian and fighter.
7- Rejection of the other, and enforcement of the unipolar principle.
8- They had no respect for treaties; nothing was easier for them than to revoke treaties and break covenants. This attribute was inherent in them, and was something which they never abandoned at any point of the history of their state since its foundation until its decline.
What is important is that the Tatars started to seriously think and plan to invade the Islamic countries and sack the ‘Abbasid Caliphate, occupying Baghdad, the capital of the Islamic caliphate.

http://97.105.52.213/en/artical/20688