In the first month of the second year of Yining (618), Emperor Gong of Sui added Li Yuan again, and at the same time named his eldest son Li Jiancheng as the left marshal, and the second son Li Shimin as the right marshal.

In March of that year, Yu Wenhua and killed Yang Guang, the emperor in Jiangdu, and established Yang Hao, the king of Qin, as the emperor, and Wang Shichong of Luoyang after Yu Wenhua and killed Yang Guang, and Yuan Wendu, Lu Chu and other Yang Tong, the king of Yue, as the emperor.

Before Wang Shichong arrived in Luoyang, he fought a battle with Li Mi, but he returned defeated, he arrived in Luoyang, after setting up Yang Hao as the emperor, he immediately pointed to Wagang Village, defeated Li Mi, recruited Wagang generals, and Luoyang soon became one of the most powerful military groups in the country.

At the same time, in May, Emperor Gong of Sui passed the edict to give way to Li Yuan, the king of Tang, Li Yuan half-pushed, and finally ascended the throne with the support of the ministers, and since then, the regime of the Tang Dynasty that has lasted nearly 300 years has begun.

After Li Yuan ascended the throne, he appointed Xiao Zao as a lieutenant, granted amnesty to all the people in his territory, exempted him from forced labor for three years, and at the same time posthumously crowned his ancestors and respected his father Li Yu as Tang Shizu, nicknamed Emperor Yuan, and his mother Lone as Empress Zhenyuan.

His deceased wife Dou was the queen of Mu, the eldest son Jiancheng was the crown prince, the second son Shimin was the king of Qin, the fourth son Yuanji was the king of Qi, and Liu Wenjing was the Sima.

It is said that Li Yuan had a tangle in his heart before he became the crown prince, he was able to make up his mind to raise troops, and finally ascend the throne and establish the Tang Dynasty, and his second son Li Shimin can be said to have contributed a lot.

If it weren't for Li Erlang's bold decision and forcing him to make a decision, with his forward-looking and backward nature, even if he had the heart, he would not have the courage.

For this reason, after he ascended the throne, for the position of the crown prince, he specially summoned several confidants and ministers to ask their opinions.

"Your Majesty, since ancient times, the position of the crown prince should be given priority to the eldest son, and the eldest son of Your Majesty has been the son of the world since he was a child, so he can learn his skills, moral integrity, and everything is the best choice, what else does Your Majesty have to hesitate about?" Pei Lin said.

The other henchmen also nodded with deep understanding, and after Li Yuan heard this, he no longer hesitated, and made up his mind to make his eldest son Li Jiancheng the crown prince.

The second son Shimin is outstanding, but the eldest son is not bad, and the most important thing is that Li Erlang's temperament is too wild, and he acts too boldly and fearlessly, like a wild horse that no one can hold, Li Yuan is somewhat uneasy.

When the court announced the canonization of the crown prince and promulgated the edict, Li Yuan also carefully observed Li Shimin's expression, and found that his face was calm, and he could not see any unhappiness on his face, and the heart he was carrying finally let go.

The brothers Da Lang and Erlang have always been close to each other, and it shouldn't be because of this, it's because I'm thinking too much, Li Yuan saw the eldest son of Chao He happily in his second son, and the uneasiness in his heart also dissipated.

Li Yuan and Empress Mu have a very close relationship, and they are very fond of her children, and after witnessing the fierce competition for the throne by the sons of Emperor Wen of Sui, Li Yuan really doesn't want to see his son come to this point one day.

On the night of the crown prince's canonization, Li Erlang drank a little too much, and was so drunk that he couldn't walk, and was sent back to the Qin Palace's mansion by his subordinates.

She first ordered someone to bring a bowl of sobering soup, and then personally served him to freshen up, and after going to bed, Li Erlang changed his previous gentleness and thoughtfulness, and became like a hairy boy when he first tasted love two years ago, fierce and rude and unrestrained.

After some tossing, the eldest grandson and the little lady only felt that everyone was about to fall apart, after the clouds and rain stopped, and the storm calmed down, Li Erlang looked at his wife who was like a flower that had been destroyed by the storm, and the eye-catching bruises on her body, and felt very guilty, he gently hugged her into his arms and apologized in a low voice: "I'm sorry, Guanyin." ”

"It's okay, you and I are husband and wife, there is no need to say sorry, Erlang is in a bad mood?" The careful and transparent eldest grandson and little lady breathed a sigh of relief, reached out and gently held his palm, raised her eyes to look at him, and said softly.

"If you really can't hide anything from Erniang, there is indeed a little." Li Erlang rested his chin on her shoulder socket, gently rubbed her smooth hair, and sighed softly.

"Is it for my father to appoint the eldest brother as the crown prince?" The eldest grandson and the little lady asked again.

"Well, I know it's not right for me to think so, the eldest brother is both a grandson and an elder, and he has been a son since he was a child, these years have come in the wind and gone in the rain, and he has been worried about his father, he is much older than me, and I was not less cared for and taken care of by him when I was young."

"Coupled with his talent and ability, no matter what aspect it is, it is a matter of course for him to be named the crown prince, I just ......" Li Erlang smiled bitterly, and his tone was quite disdainful of himself.

"I can understand Erlang's heart, my Erlang, since he was a child, has great ambitions, not a person who is willing to be subordinate, plus you are open-minded, martial arts, everything is outstanding, it is difficult to find a person in the world who can match you, now the Tang Dynasty has been established, and the prince has decided to ......"

"It's human nature that you feel a little lost in your heart, but as you said, the eldest brother was made the prince, no matter what aspect it is, it is reasonable, Erlang ......" After listening to this, the eldest grandson and the little lady were slightly silent for a while before speaking.

"I understand what you mean, Guanyin, rest assured, I will adjust my mentality, assist my father, eldest brother, and be a good generation of virtuous kings.

"There are anti-kings everywhere outside, and there are not a few soldiers and horses whose territory is not under our Li family, and if you want to really dominate the world, I don't know how many years it will take, and I am thinking about these things now, which is really redundant and funny."

"In ancient times, Duke Zhou wholeheartedly assisted two generations of emperors and achieved good stories through the ages, I, Li Shimin, asked myself if my mind would not be inferior to him, can Duke Zhou do it? How could I not do it? Li Erlang hugged his wife tighter and said with a smile.

It's a pity that things in the world are unsatisfactory nine times out of ten, Li Erlang has the heart to be the Duke of Zhou, but there are not necessarily King Wu of Zhou and King Cheng of Zhou in the world.

Of course, these are all later words, the current relationship between the father and son of the Li family is still very close, brother and brother, father and son are filial piety, Li Shimin saw that his brother was named the prince, although his heart was a little depressed, but he had no intention of pulling him off the horse.

Li Jiancheng also had no intention of dealing with his younger brother, and at this time, the eyes and muzzles of the Li family were all aimed at the enemy outside.

In July of that year, Liu Jing fought with Xue Ju in Jingzhou, returned defeated, and was cut by Tang Gaozu, and soon after, Xue Ju died of illness, and his son Xue Rengao succeeded to the throne, and after Xue Rengao succeeded to the throne, the newly established Tang Dynasty immediately launched a fierce attack.

After the hussar general Liu Gan and Longzhou Assassin Shi Changda were successively defeated by Xue Rengao, Li Yuan ordered Li Shimin, the king of Qin, to serve as the generalissimo of the Western Expedition and conquer Xue Rengao.