In The mid-twelfth century.The Mongols were just one of manys peoples in the Eastern grasslands,neither particularly numberous nor especially advanced. Then,Mongolians began to expand because The Decline of annual average temperature caused the survival crisis. With the Shrinking of pastures, Mongolians and other nomads have to look beyond the Grasslands to get more food from the agricultural world. The second reason for Mongolia's sudden rise is the emergence of Genghis Khan. Genghis Khan and his successors were able to conquer Asia and Europe not only because of the Mongolian army's strong fighting Ability and advanced weapons, but also because of their army's fighting methods And skills.2222. The success of the Mongols in ruling vast territories was due in large part to their willingness to incorporate other ethnic Groups into their armies and governments . Whatever their original country or Religion ,those who served the Mongols loyally Were rewarded . The Mongols were Also open to trying new military technologies .To attack they employed Chinese catapults .At First Turks in Afghanistan were more Powerful ,they adopted the better model .The Mongols also used exploding arrows and gunpowder projectiles developed By the Chinese . The Mongols made good use of intelligence and tried to Exploit internal divi - sions in the countries they attacked .Thus in north China they appealed to the Khitans ,who Had been defeated by the Jurchens a century earlier ,to join them in attacking the Jurchens .In Syria they Exploited the resentment of Christians Against their Muslim rulers . 22Genghis Khan and his descendants used these methods to gradually expand to Europe, Poland in the west, India in the south, Japan in the East, Siberia in the North, Moscow in Russia in the northwest, Egypt in Africa in the southwest, Java in Indonesia in the southeast, Myanmar and Vietnam in the south.222The Mongols adapted their methods of Government to the existing traditions of each place they ruled ,and the regions went their separate Ways . In China the Mongols resisted Assimilation and purposely avoided many Chinese practices. In Central Asia ,Persia ,and Russia the Mongols tended To merge with the Turkish groups already There and ,like them ,converted to Islam .222In conclusion, Genghis Khan Launched the largest war in human history, created the largest country in the World, and was the most influential person in the world history.