In ancient times, our dynasties and dynasties were ruled by the Central Plains as the core, at that time the transportation was inconvenient, the information could not be transmitted quickly, so the frontier lands were difficult to govern, so there would be many nomadic peoples in the northern border lands of our country that were difficult to control, such as: Xiongnu, Turks, Jurchens, and some other ethnic groups, in the Wei and Jin Dynasties, there was a powerful alliance tribe, this tribe is Ruoran.
Rouran is a powerful tribe in the Mongolian steppe after the Xiongnu and Xianbei, it belongs to a branch of the Xianbei, when the Central Plains was in the chaotic period of the Southern and Northern Dynasties, Rouran rose rapidly, and formed an opposition to the Northern Wei and Southern Dynasties, their purpose is to advance into the Central Plains and rule the Central Plains, their main nomadic area is in the current Mongolia, but when they grew, their nomadic areas were expanded to the Baikal region of Russia and the western region of our ancient China. It is now the Xinjiang region.
This incident took place during the Southern and Northern Dynasties, and the protagonist was a man named Sima Chuzhi. Sima Chuzhi was familiar with military books, quite strategic, and a rare general. The Northern Wei emperor Tuoba Tao took a fancy to Sima Chuzhi at a glance and appointed him as the Great General of Annan and the Assassin of Jingzhou. Sima Chuzhi lived up to expectations, defeating Liu Song's army several times, and soon became Tuoba Tao's right and left arm. Later, Tuoba Tao led troops to attack Rouran and appointed Sima Chuzhi as the grain inspector, who was fully responsible for supervising the grain and grass.
During a tour, he found that the donkey carrying the grain was missing one ear, and it was not long after the situation was cut, and after questioning, the soldiers in the army said that they had not done it themselves. This incident attracted Sima Chuzhi's attention, because he had been in contact with the Rouran tribe in the north in his early years, and he knew that the secret agents of the Rouran tribe used to cut off the ears of a donkey when inquiring into military information, so he judged that there were recently Rouran spies mixed in the army, and the war was likely to happen immediately.
He immediately informed the whole army: Prepare for battle immediately, the enemy is coming! So the whole army began to build the city, because he had made full preparations in advance, and after the Rouran people came, they saw that the people had built a big city, and they were only good at killing the grassland people on the flat ground, so they had to return to the same way. Sima Chu's wisdom was superior, and he guarded Northern Wei and Northern Jiangsu for more than twenty years, and his military achievements were outstanding, and he was named the King of Lang Evil. Heaven favored the wise man, and Sima Chuzhi died at the age of seventy, which was a relatively high life expectancy at that time.