In our current view, the Tang Dynasty was a fairly powerful dynasty, with territory as far away as Central Asia, a powerful country, and its martial arts surpassed other dynasties, enough to rival the Han Dynasty. However, when the Tang Dynasty was first established, it was not so powerful, because the country was created and civil strife continued, so Li Yuan once had to submit to the Turks, and it was precisely because of this that the early Tang Dynasty often exchanged peace for temporary peace in the form of peace, which was criticized by posterity.
However, Tang Taizong was also a male lord of a generation, and although he did not oppose peace, he really wanted his own daughter to be a wife for the people of the backward foreign countries, and he was still quite disgusted, unless the country was particularly important, such as Tubo, or he had no way, he had to do it.
In 630 AD, the xueyantuo state in the north of the Tang Dynasty gradually became stronger by taking advantage of the chaos in the Central Plains, and the forces in the north were generally like this, and when the Central Plains were strong, they would control them, for example, Emperor Wen of Sui and Emperor Sui took the Turks to death, and the Sui Emperor also deliberately ran to the north with a group of people to intimidate the Turks, and they had to "cut in front of the tent, do not dare to look up", and let the Sui Emperor whip.
The Sui Dynasty collapsed due to internal forces, and the emerging Tang Dynasty did not have the influence of the Sui Dynasty at that time, and at this time, the xueyantuo state and other countries in the north let themselves go and grew rapidly. When Xue Yantuo's kingdom was at its peak, its army reached 200,000 - all of them were cavalry, so Li Shimin was very jealous of him, "Emperor Taizong was also strong and prosperous, and he was afraid of future troubles." ”
Li Shimin used the method of uniting other tribes to attack xueyantuo, which gradually weakened xueyantuo. Due to the many contradictions within xueyantuo, during the decline in national strength, civil unrest began to break out, and at the same time, other departments on the grassland also began to prepare to deal with Xueyantuo, and for a while " the offensive and defensive momentum was different". At this time, the Yinan Khan of Xueyantuo (that is, the king of Xueyantuo) thought of uniting the Tang Dynasty at that time, so he sent someone to ask for the princess of The Tang Dynasty.
It is reasonable to say that Li Shimin should not have helped The Yinan Khan of xueyantuo at this time, but on the one hand, the rise of the Turks in the north, if the Yinan Khan is now thrown into the arms of the Turks, the consequences are unimaginable, on the other hand, if the Yinan Khan directly commands his troops to the south and diverts domestic contradictions through war, it is also a very big threat to the Tang Dynasty, which is in urgent need of repair at that time.
So Tang Taizong asked the ministers to discuss, and the ministers came up with two plans, either "selecting a hundred thousand soldiers to strike, making no one lose, and calculating for a hundred years" - this plan is of course good, and it will solve the problem permanently at once, but at that time, the Tang Dynasty was still difficult to bear such a big price, 100,000 people ate and drank Lasa, which could drag the Tang Dynasty half to death; or let the princess marry Xue Yantuoguo, "bondage makes boundless worry, thirty years of calculation."
However, these two strategies Tang Taizong was not satisfied, although the princess was Li Shimin's daughter, it was her father's little cotton jacket, and she was thrown to the bitter cold desert in the north, although Li Shimin, who killed his brother and forced his father, could not do it. At this time, a person stood up and proposed an idea, which made Li Shimin suddenly happy.
This person is called Qifu HeLi, he himself is also a figure on the grassland, later turned to the Tang Dynasty, got the Tang Taizong's reuse, holding the attitude of a soldier who dies for a confidant, Qifu He Li used the mentality of Yi Nan Khan to analyze, put forward a brilliant plan, he asked Xue Yantuoguo to prepare a rich dowry for the princess, if Yi Nan Khan could not do it, the Tang Dynasty could repent of marriage with courage. And the Khan of the Kingdom of Xueyantuo:
"If a man is strong and fierce, he will not marry, and he will return to the second place, but in a year or two he will die of illness, and if the two fight, they can sit on the throne."
This clever plan made Li Shimin very satisfied, on the one hand, there was no need to send troops to attack Xue Yantuoguo, on the other hand, for the time being, he could not send the princess to the foreign country, drag it out for a while, maybe Xue Yantuoguo himself would perish, so that his lovely daughter would not run to the bitter cold desert to be a wife with strangers.
Therefore, Tang Taizong agreed to Yinan Khan's request and told him to "sacrifice 50,000 horses, 10,000 heads of cattle and camels, and 100,000 sheep" and get the treatment of "emperor general Xingling Prefecture to marry" The high-standard Tianzi personally held a marriage for him.
This temptation is not small, Tang Taizong personally went to Lingzhou to hold a wedding for him, which has not been done in the history of the Tang Dynasty, nor has it been in the history of China, and there is no need to worry about Li Shimin persecuting him with this, no matter how unexpectedly he is militarily attacked, the Tang Dynasty, as the Central Plains Dynasty, always pays attention to credibility in politics, and if Li Shimin uses this to booby-trap him, it is almost self-extinct. 、
And The dowry that Tang Taizong wanted did not seem to be very expensive—cattle, horses, camels, and sheep were the most common animals in the grasslands, Xue Yantuo was everywhere, and the nomadic tribes did not have a tradition of careful statistical work, in fact, he did not know what this data meant. But Li Shimin must have asked his subordinates to carry out careful mathematical calculations, Datang's mathematics is not covered, this data will not make Xue Yantuoguo feel very large, and at the same time, it can consume Xue Yantuo's national strength to the greatest extent.
Sure enough, Yinan Khan mobilized these animals from the country and collected them from the tribes below, in fact, it could still be expropriated, but in this way, the life of the poorer tribes below was very difficult, and This move of Yinan Khan caused widespread public anger, but this could not resist Yinan Khan's pursuit of the beautiful women of the Tang Dynasty, and he painstakingly gathered animals to transport to Lingzhou, and there were many sick and dead on the way, plus the transportation suffering, and the date of Yinan Khan's dowry was overdue.
So Li Shimin repented of his marriage righteously, And Yi Nan Khan was very angry, but he had nothing to say, Li Shimin neither deceived him nor lost faith, but he himself agreed to the Tang Dynasty's dowry but could not deliver it on time and in quantity, so he had to drive these cattle and sheep back with another belly of birds - the whole grassland was watching his jokes, and the grumpy Yi Nan Khan died of anger not long after he returned.
After the death of Yinan Khan, his son's prestige was insufficient, although he succeeded to the throne, he could not control the large tribes below, and at the same time, because Yinan Khan wantonly collected "dowry gifts" from the tribes below, he lost the hearts of the people, and finally civil unrest broke out, and finally Xue Yantuo's kingdom was destroyed, which was equivalent to Tang Taizong destroying Xue Yantuo's kingdom without spending a single soldier.
Datang has fought so many battles, and although it has won a lot of battles, it has never won so thoroughly and easily like this time.