As the fourth year of Zhongping approached, the air in Youzhou became tense, and at this moment, Liu Zhuo once again convened his subordinates to discuss the matter.

Liu Zhuo sat in the general's mansion, surrounded by the twins Siqin and Siqi, who were handsome women dressed as men, and the ugly Han Dianwei stood on the edge of the seat like a black iron tower. On the left of the hall are civil officials, and on the right are military generals. This time, though, there are a lot of new faces.

After the hall was silent, Liu Zhuo spoke: "At present, the top priority in front of us is to completely solve the security of Youzhou, everyone knows that Youzhou is very complicated, various ethnic groups live together, and the Han nationality is often violated and looted by foreign races. Next, let me first let the great Confucian Cai Zhonglang briefly introduce the situation of several large alien races in Youzhou. ”

Cai Yi walked out and arched his hand up and down, and said: "At this stage, the two main ethnic minorities that pose a big threat to Youzhou are Wuhuan and Xianbei. These two ethnic groups are the descendants of an ethnic minority called "Donghu" during the Yin Shang period. In the early years of the Western Han Dynasty, the Xiongnu led troops to eliminate Donghu in Maodun, and it is said that the remaining people of Donghu fled to "Wuhuan Mountain" and "Xianbei Mountain" respectively, and since then they have multiplied, and they also took their respective mountains as their clan names, and the Wuhuan and Xianbei tribes were born. Of course, there is also a theory that the Wuhuan people are the descendants of Xia, and the Xianbei people moved from within the Xing'an Mountains. Tuoba Xianbei originally lived in the deep mountains of the Daxing'an Mountains, when the Tuoba Xianbei tribe had low productivity, did not form a developed animal husbandry, and was still in the primitive nomadic economy era. Due to the depth of the Great Xing'an Mountains, the further development of the tribe was restricted, and later the leader of Tuoba Xianbei led his troops to leave the Great Xianbei Mountain, and moved south to Daze, more than 1,000 miles. The large swamps and numerous small lakes were not suitable for the nomadic Xianbei tribes, so they continued to migrate south. Because the climate has become cold and dry, the Wuhuan and Xianbei tribes are facing a harsh environment with reduced pasture grass and frequent disasters, and they have to go south to find new areas suitable for grazing. During the Qin and Han dynasties, China was in a warm and humid period, but from the perspective of climate change at that time, after the middle of the Western Han Dynasty, the climate gradually tended to be cold. This severe cold weather also affected the northern steppe regions. In 71 BC, the Xiongnu defeated Wusun and encountered heavy snow on the way back, freezing tens of thousands of people to death. The Xiongnu, who were once the overlords of the grasslands, were powerless to resist natural disasters, let alone Wuhuan and Xianbei. Although the historical records do not clearly record the natural disasters they faced, it can be inferred from the situation of the Xiongnu that the living conditions of Wuhuan and Xianbei are also very severe. Due to its location in the northeast, the first thing to bear the brunt of is the severe cold weather. The persistence of cold weather has thickened the frozen ground and lengthened the pasture growth period, which is not conducive to grazing more livestock. In addition, severe cold weather will lead to an increase in drought and locust plagues, which will cause the grassland to dry up and dry the land for thousands of miles, and livestock to die. As nomadic tribal peoples, they are unable to take effective measures to deal with the losses caused by natural disasters, and the only way is to keep moving south, closer to the Central Plains, and looking for more suitable areas for pasture. ”

Cai Yi paused for a moment to let everyone digest these contents, and then continued: "Wuhuan and Xianbei both lived in the original Xiongnu area, in the middle of the Eastern Han Dynasty, one of the leaders of the Wuhuan tribe led the clan to move inward, and was allowed to settle near several counties in Youzhou, and was responsible for recruiting other Wuhuan people to come to take refuge. These internal Wuhuan later gradually developed three large strongholds in Youzhou, namely Liaoxi Wuhuan near Liaoxi Kingdom, Shanggu Wuhuan near Shanggu County, and Liaodong Wuhuan near Liaodong Kingdom, which are generally collectively referred to as Sanjun Wuhuan. Although the Wuhuan people who moved inward were protected by the Han Dynasty for a long time, they did not really thank the Han Dynasty for the help they gave, and the Wuhuan people in the three counties were the most powerful, often leading other small migrating tribes to participate in the robbery of the counties, and even colluding with the rebel parties to launch rebellions. But now, because the ruling power of the Eastern Han Dynasty is showing signs of decline, they are unable to take care of the nonsense of these Wuhuan people, so they are quite unscrupulous. ”

Of course, Wuhuan is not always like this, among the Wuhuan people who moved inward, a large part of them were also recruited as soldiers by the Han Dynasty, they were generally stationed in various border guards in Youzhou, scattered in many troops, and were often sent to resist the invasion of Wuhuan or Xianbei people. Therefore, it can be said that so far, the Wuhuan people are still in an extremely fragmented state of division, some of them stay in their homeland outside the Saiwai, and the other part moves inward, scattered in the counties and counties of Youzhou, some of them rob the Han Dynasty with others, and some protect the Han Dynasty with others. In short, the Wuhuan at this time is still relatively weak, but their riding and hunting level is not to be underestimated. ”

The civil and military forces in the lobby listened quietly to Cai Yi's narration, some people knew these things, but most of them were not very clear, and it was the first time they heard such a detailed description, especially those from the inland of the Central Plains. Cai Yi continued to narrate: "Xianbei's situation is much better than that of Wuhuan, after the decline of the Northern Xiongnu, Xianbei occupied the original Xiongnu's hometown, and after Wuhuan moved inward, Xianbei occupied their land again, and the Xianbei people gradually showed signs of recovery and prosperity. In short, it was the geographical environment and climate that caused the Wuhuan and Xianbei tribes to move south, so that they had to go south to find more suitable areas for pasture, so that they expanded to areas inhabited by the Han people. Before Wuhuan and the eastern Xianbei moved south, they were mainly active in the forest and grassland area of the West Liao River Basin, starting from the Bahrain Left Banner on the north bank of the West Liao River in the north, north of the Xilamulun River in the south, starting from the southern section of the Daxing'an Mountains and Qilaotu Mountain in the west, and reaching Liaoyuan in the east. Within this range, it mainly includes the West Liao River, the Xiaoling River Basin, the Yanshan Mountains and other geographical areas. Moreover, there are many sand dunes in the area of the West Liao River, and the south bank is the Horqin Sandy Land, in which there are grassland lowlands and impact plains, which are semi-agricultural and semi-pastoral areas. The west is bordered by the southern foot of the Great Khing'an Mountains, the eastern foothills are mostly forested, and the Yanshan area in the south is composed of middle and low hills and basins. In this diverse geographical environment, their main economic and ecological regions are the hilly forests and grasslands at the eastern and southeastern foothills of the Daxing'an Mountains, the Xiaoling River, and the northern foothills of the Yanshan Mountains. Because grazing requires different pastures depending on the season, and it takes a lot of manpower to take care of livestock, find pasture and water sources, and respond to seasonal changes and disasters, it is impossible for them to raise more livestock in the geographical environment of mountains, hills, and forests. As a nomadic people, such geographical conditions are very unfavorable for their development. ”

Cai Yi roughly introduced the situation of Wuhuan and Xianbei, so that everyone had a clearer understanding of this. It turned out that these Wuhuan and Xianbei tribes had moved from the cold areas in the north, and they had to make chaos when they occupied the territory of the Han Dynasty, and they couldn't stay.