The brutal massacres and slaughters were accompanied by mongols invasion and conquests throughout the entire 13th century in most area of Asia and East Europe. The mongols not only bringing the practical brutality but also the destruction of the civilization to the human history. because of special censorship on Chinese characters , I have to use English which i am not good at to write about the content that may involved Chinese political correctness. Any allusion to the Mongol decimalization of the human world may not be welcomed by Chinese government. somehow, the relatively tight political situation in China is impeding Chinese people to know the history that generally recognized and accepted by the world. It makes to the Chinese people have the special perspectives and views on the history which comprise the very strong nationalism standpoint. as a consequence, many perspectives on history that most Chinese have biased nationalism even against to the human traits and morality.
The tallest Genghist Khan statue in the world located in Songyuan, China
(picture is from Baidu image)
Therefor, I want to summarize the mongols outrages based on documented historical materials and present the perspective of the history that was generally accepted by the historians.
The subjugation of Western Liao
After Temujin wined the reunification of the war against all the nomad tribes in the Mongolian steppe , the tribes and clans were successfully united and reformed into a ethnic Mongol Empire in the early of the 13th century. He assembles all the chiefs of the tribes to form a council called Kurultai at 1206, the Kurultai council gave him the title of Genghis Khan at the same year. In 1209, the Mongols began to the first invasion against the closest empire called Western Liao dynasty. The details of the war is not quite clear, but based on limited documentation the mongols had significant success on the open battles. nonetheless the mongols still had a lot difficulty to take the fortified cities. the mongols first gained experience to siege the cities in these wars . The surrounded cities slowly succumbed to starvation and diseases. The Liao emperor had to submit to Genghis Khan and become his vassal.
The conquest of Jin Dynasty
Meanwhile, the Jin dynasty was high alerted by Liao surrender at 1211. at same year Mongols promptly turned attention to Jin dynasty which located the northern China. Because Jin had more population and more powerful the militar forces and fortresses than Western Liao, this actually caused the underestimation to about Mongolians. Jin had the 800,000 infantry which mostly were unchained peasants, and 150,000 highly-trained heavy cavalry. This army were spread across the Great Wall and garrisoned separate fortresses . In contrast, Mongols only had 90,000 strong cavalry army which comprise three main components: light cavalry scouts, horse arches and heavy cavalry armed with lance and curved swords. Although Numerically, Jin had significant advantage than the Mongols , all of the mongols soldiers were highly-trained and loyal.
The Mongols easily bypassed the Great Wall , after that mongols split into two armies. The main army was 60,000 led by Genghis Khan. The rest were taken by his third son Ogedai with 30,000 people to attacked city Datong (大同). Meanwhile, Genghis Khan's 60,000 army headed to Juyong Pass ( 居庸关) which protected Beijing. He soon encountered the massive Jin army at Yehuling (野狐岭) and stopped by them. For months the mongols had been waited the Jin to make move, but they kept the defensive posture. Genghis send 2 small forces led by his most trusted 2 generals , Jebe and Subutai to attacked the west front fortress called Wuxia battle. The Wuxia fortress were razed by Mongols assault. After the the 2 small forcess grouped up to the main force which were still waiting at Yehuling, the mongols started attack the defenders at and push the Jin defenders back. Genghis sent over the peaks to surrounding the pass which the Jin generals thought was impossible and attack the Jin army from both sides. after Jin keep the defensive posture to held ground in the fortress , Jebe use the trademark Mongol tactic of a feigned retreat, which is pretending flee to leave loot while they fled. The Jin defenders were tricked and left their fortifications to chase them down. they did not know they were falling into a deadly trap, where thousands of them were attacked from all sides by Mongol archers. The gates of China was clear and open to mongols after big win of the battle of Yehuling. The most efficient defend pass and gates Yehuling were razed by mongols, which means China was like a open field to Mongols. without mountains terrain fortress Yehuling to protect, the Beijing and surrounding area were easily raided by Mongols cavalry. It is impossible to win the battle against mongols on the plain or open field. Winter was coming, Genghis Khan decided to withdraw. In general this military action was successful even though not gained many loots, sweeping away the obstacle for following military actions against Beijing. This invasion was well known as Battle of Yehuling (野狐岭战役).
As expected, Mongols struck China again in the following year. The mongols did not meet the efficient and fierce resistance from Jin like previous invade. They easily across the mountain terrain without any resistance and besieged multiple fortress and cities located surrounding Beijing , waited the Jin army from Beijing city to sally to break the sieges. The Jin army to be ambushed and eliminate by mongols easily on the open field. Without reinforcements the cities and fortresses did not stand much longer, they soon surrendered. The most of inhabitants of these cities were murdered or enslaved. However, only engineers, artisans, merchants, doctors, teachers, priests, and administrators were spared and be absorbed by mongol forces. the left were taken as the meat shields for the following sieges to discourage the defend arches from firing and marching in the vanguard to block arrows. After destruction and razed all the cities and fortress, Genghis Khan moved to against capital of the Jin empire, Beijing, and besieged it. The mongols tried to starve the city out, but after few months an epidemic spread through their camps. they had to negotiate with Jin emperor,Xuan zong(金宣宗), the 8th emperor of Jin dynasty. He had a peace agreement with Genghis Khan , but as the exchange he had to tribute loot,men, horses, and even his daughter to mongols. In the end, Mongols planed to left China and returned to Mongolia with the treasure. but when they outside the Great Wall, a messenger galloped to Genghis Khan, that Xuan zong (金宣宗) had moved his court to Kaifeng (开封). The mongols quickly to return to Beijing besieged the city. The city was surrounded, breached, and razed. For weeks, thousands of carts hauled back to Mongolia. The fires in the city burned over a month while its people were massacre. The entire north China was completely conquered and controlled by Mongols.