When the Central Plains Dynasty is strong, it will depend on you. If the Central Plains dynasty declines, it will also seize the opportunity to occupy the frontier land. Therefore, whenever the internal disputes of the Central Plains Dynasty end, it is necessary to teach it a lesson again.
During the Qin and Han Dynasties, Vietnam was briefly ruled by the Central Plains Dynasty. Both Qin and Han dynasties set up counties in Vietnam. Later, in the Tang Dynasty, the world was in chaos at the end of the Tang Dynasty, and the local power of Vietnam was growing day by day. It took the opportunity to unify the whole of Vietnam and establish a dynasty.
Vietnam is also a Central Plains dynasty gradually separated from it. Vietnam was called Jiaotoe, Jiaozhou and Annan in ancient times, and the name Vietnam did not appear until the Qing Dynasty.
The Central Plains Dynasty and Vietnam really started a large-scale war, or from the end of the Tang Dynasty.
The Southern Han Dynasty perished and the Ding Dynasty perished. After the Tang Dynasty entered the Five Dynasties and Ten Kingdoms period, Vietnam was under the rule of the Southern Han regime at that time. Later, a man named Ding Buling unified all the tribes in Vietnam and officially proclaimed himself emperor in 968.
Before that, Vietnam was a vassal state of the Central Plains Dynasty, and their rulers only called themselves kings. After Dante Buh unified Vietnam and proclaimed himself emperor, it officially became an independent country.
For Vietnam's independence, of course, the Nanhan regime did not allow it, so Nanhan marched eastward to Vietnam, but was ambushed on the way, and the Nanhan army finally lost.
After the Northern Song Dynasty and the Northern Song Dynasty of the Li Dynasty unified the Central Plains Dynasty, the Ding Dynasty of Vietnam took the initiative to make the Song Dynasty a vassal state for fear of punishing them. Zhao Kuangyin saw this Ding Dynasty and surrendered voluntarily. The main enemy of the Northern Song Dynasty was in the north, and he didn't have the energy to punish Ding Dynasty in the south, so he accepted the request of Ding Dynasty.
After the Ding Dynasty was attached to the Northern Song Dynasty, the Northern Song Dynasty awarded the title of King of Jiaojiao County to their emperor, but not long after, Lê Hoàn, a powerful minister within the Ding Dynasty, usurped power and established the Li Dynasty.
After the establishment of the Li Dynasty, it broke off the relationship between vassal and vassal with the Northern Song Dynasty. Song Taizong and Zhao Guangyi, let's see what qualifications you have to be my equal. That won't do, but we still have to fight.
So the Northern Song Dynasty began to crusade against the Li Dynasty. Later, the Northern Song Dynasty was ambushed like Nanhan in the war. The Northern Song Dynasty, which failed in the crusade, had to recognize Li's position, and Vietnam entered the Li Dynasty.
Shortly after the Northern Song Dynasty and the Li Dynasty entered the Li Dynasty, a powerful minister, Li Jue, rebelled again, usurped Li's throne and established the Li Dynasty. After the establishment of the Li Dynasty, they began to be restless, and they even took the initiative to attack the Song Dynasty.
Under the attack of the army of the Li Dynasty, a large number of people died and occupied a large area of land in Guangdong and Guangxi adjacent to Vietnam. When Song Shenzong saw this, he had to fight back hard, so the Northern Song Dynasty organized a large number of troops to crusade against the Li Dynasty.
The Northern Song Dynasty attacked Vietnam from Yunnan and Guangxi, and at the same time attacked Vietnam from land and water. The Li Dynasty retreated under the attack of the Northern Song army. After Song Jun attacked Hanoi, the Li Dynasty chose to surrender to the Northern Song Dynasty and compensate a lot of treasures.
Shortly after the Song, Yuan and Chen Dynasties surrendered to the Li Dynasty, a powerful minister named Chen Shoudu usurped the throne and established the Chen Dynasty. Shortly after the establishment of the Chen Dynasty, the Song Dynasty in the north did not crusade against him, because the Song Dynasty was quickly destroyed by Mongolia. After the destruction of the Song Dynasty, Mongolia established the Yuan Dynasty and began to crusade against the Chen Dynasty.
Chen's army is no match for Mongolian cavalry at all, but despite the history of Mongolian cavalry, their water war is no good. Chen's royal family took a boat and went to the seaside to hide. Seeing that they could not be caught, the Mongols retreated voluntarily.
However, on the way to the retreat of the Mongolian army, Chen Chao's army actually landed from the water and launched a counterattack against the Mongolian army. In the face of Chen Chao's comeback, the Mongolian army once again launched an attack on Chen Chao.
The Mongolian army's second attack on Chen Dynasty ended in failure. After two failed conquests against Chen Dynasty, Kublai Khan, the ruler of Yuan Dynasty established by Mongols, was always worried about this, so he launched the third war against Chen Dynasty.
Because of the water army, Chen people no longer ran into the sea. They all hid in the mountains and then attacked the Yuan Army from time to time. Over time, because the Yuan Army could not completely destroy Chen Jun and could not persist for a long time, it finally gave up the crusade against Chen Chao.
After the Ming Dynasty established the Ming and Hu Dynasties, the Chen Dynasty took the initiative to become a vassal state of the Ming Dynasty. When Zhu Yuanzhang saw that Chen Chao was well informed, he agreed to Chen Chao's request, and pointed out that Chen Chao and North Korea were both countries that did not levy.
But it didn't take long for Li Jihuan, a powerful minister of the Chen Dynasty, to usurp power and stand on his own feet. Because this Li Jihuan changed his surname from Hu to Li, the dynasty he established was called Hu Dynasty.
After the Chen Dynasty was usurped by Li, they went to the Ming Dynasty, the suzerain country, for help. When Judy, the founding emperor of the Ming Dynasty, saw that her younger brother was bullied, she should help him to be the boss, so Judy sent the Ming army to destroy the Li Dynasty.
After the Li dynasty was destroyed by the Ming dynasty, it did not let the Chen dynasty restore the country, but directly set up a government Council to directly govern and rule.
Shortly after the Ming Dynasty ruled Vietnam again, during the reign of Emperor Ren Xuan II, the Ming army was defeated by local tribes in succession in Vietnam, and finally had to withdraw from Vietnam and once again recognized its independent status.
After the demise of the Qing Dynasty and Ruan Ming Dynasty, the Qing Dynasty took advantage of the division between the north and the south of Vietnam and extended its tentacles to Vietnam. The Qing army once occupied northern Vietnam, but was quickly defeated by local forces in Vietnam, and finally had to give up the conquest of Vietnam.
Vietnam survived several times under the attack of the Central Plains Dynasty. The fundamental reason is that Vietnam is far away from the hinterland of the Central Plains Dynasty, and they gradually formed their own culture.
Therefore, every time the Central Plains Dynasty entered Vietnam, it was impossible to completely occupy Vietnam. War can only win for a while, and it cannot dominate other cultures ideologically, so it cannot be occupied for a long time. This is the fundamental reason why the Central Plains Dynasty failed in sending troops to Vietnam many times in ancient times.