Since the pacification of Hedong, the prestige of the Tang Dynasty has become increasingly prosperous, and all the people in the world have returned to their hearts.

However, at this time, many separatist forces still existed, such as Wang Shichong of the Central Plains, Dou Jiande of Hebei, Luo Yi of Youzhou, Xiao Milling of Jiangling, and Du Fuwei of Jianghuai, all of which had become their own forces.

As early as more than 1,000 years ago in the Warring States Period, there were Guiguzi's high-footed Su Qin and Zhang Yi who planned it.

Su and Zhang and the others, through the strategy of combining vertical and horizontal, and the three-inch incorruptible tongue, actually said that the kings of the world would obey them, so as to determine the direction of the world.

Li Yuan has been up and down in the Huan Sea for half his life, and he has long understood the world, and if the Tang Dynasty wants to go east, he must first target Wang Shichong and Xiao Miao.

But Dou Jiande of Hebei is very strong and is the prince he fears the most.

According to the current situation, if you want to go east, you must first stabilize Dou Jiande.

At this time, Dou Jiande had established Great Xia and proclaimed himself the King of Xia. He set the capital in Zhaozhou, built a lot of construction, and built an attic. Because of the restoration of the virtue and politics of the era of Emperor Wen of Sui, in Hebei, the people lived and worked in peace and contentment, and the people were happy.

Dou Jiande was known as chivalrous when he was young, he was the first generation of heroes to raise troops, he raised the army for ten years, heroic and heroic, and laid down the territory of the entire Hebei.

However, the price was also extremely heavy, and the anti-Sui uprising in the early years left him with the loss of most of his relatives.

At this time, Dou Jiande, who was becoming more and more stable, married the daughter of the Cao family, a wealthy family in Hebei. This woman rides a horse and shoots arrows, swords, guns, swords, halberds are all fine, and she is a narrow person, and she has many suggestions and helpful suggestions for Dou Jiande.

Cao gave birth to a baby boy for Dou Jiande, which soothed the pain of Dou Jiande's loss of relatives over the years, and also made Dou Jiande, who was nearly forty years old, experience happiness in his career.

In order to celebrate the birth of the child, Dou Jiande commissioned craftsmen to build a large-scale Xia Wang Palace.

Shortly after the completion of the Xia Palace, envoys from the Tang Dynasty came to Yuzhou, and they asked to meet the Xia King and present his credentials.

The Tang envoy came and treated Dou Jiande with the courtesy of the Son of Heaven, and brought heavy gifts - 10,000 taels of gold, 30,000 taels of silver, 2 boxes of agate pearls and jade, 30,000 silk silks, and 100 blue fox mink skins from the north.

The Tang envoy also handed over Li Yuan's handwritten letter - "I recently heard that King Xia was happy to have a noble son and moved the capital to Zhaozhou, which is really gratifying. King Xia is a generation of benevolent lords, in addition to the strong to help the weak, protect the people, and win the hearts of the people. I, Datang, rose up in Guanzhong and saved the people from fire and water. Although Tang Xia is thousands of miles apart, they are like-minded people, and they should form an alliance! Wang Shichong deceived the king, poisoned the people, and committed heinous crimes. My Datang will not only conquer Luoyang in the east, but also hope that the king of Xia will protect the territory and the people. Between Tang and Xia, each side is safe. ”

Dou Jiande saw that Li Yuan's words were sincere, and besides, he had always had a bad relationship with Wang Shichong, so he readily agreed to the Tang envoy.

In order to show his sincerity, he specially ordered all the captives of the Tang Dynasty to be returned at this time.

The reason why Li Yuan treats Dou Jiande so politely is that Dou Jiande is strong, he has taken possession of the entire Hebei region, has a large number of generals, and is supported by all the people, and is the most powerful and powerful among the many separatist regimes.

However, for other separatist regimes, Li Yuan was not so polite.

For Luo Yi in Youzhou, Du Fuwei in Jianghuai, and Li Yuan recruited with the gift of a courtier. He gave Luo Yi the surname Li, crowned him the king of Yanjun, and promised him a promise of a generation of ministers. For Du Fuwei, he was given the surname Li and was crowned King Wu, perhaps with the promise of a generation of ministers.

Li Yuan was about to carry out the Eastern Crusade, so he used Huairou means to appease the forces in the distance. As for the nearby Luoyang Wang Shichong and Jiangling Xiao Miao, he was ready to press the border.