PS: Between January and May of the first year of Wude, what was Li Shimin doing? I haven't been able to find out.

As the most active planner of the Jinyang Yuebing, and also the pioneer of the Tang army's southward movement, Li Shimin rushed too fiercely, when most of the Tang army was still besieging Qu Tutong in the east of the river, Li Shimin had already crossed the Yellow River, and swooped down to Chang'an in the south, and quickly recruited all kinds of rebels and thieves in Guanzhong because of the battle of Huoyi and Qu Tutong was surrounded by the favorable opportunity, and quickly broke through the Sui army's unprepared multiple defense lines, and did not stop until the suburbs of Chang'an City. Li Shimin's troops had also grown to tens of thousands at this time, and Chang'an was shaken by this, and Li Shimin then stationed his army in a favorable terrain, on the one hand, to deter the defenders of Chang'an and possible reinforcements from other aspects of Guanzhong, and on the other hand, to wait for the arrival of Li Yuan's army.

Then, there was no then, in the fierce siege battle that began on October 25 and ended on November 9, despite the fierce resistance of the defenders of Chang'an, the generals of the Tang Army also suffered many losses, and finally, bravely climbed the city wall of Chang'an, and took the lead in attacking the warriors in Chang'an City, but it was the general under the command of the prince, surnamed Lei, and named Yongji.

At this time, what was Li Shimin doing, it was recorded in the history books of later generations that Li Shimin attacked the north gate of Chang'an City on the order of Li Yuan, and as for the subsequent events, there was no record in the history books, and then soon, because of the invasion of Xue Ju of Western Qin, Li Shimin would move westward and face a powerful enemy. You must know that the offensive and defensive battle of Chang'an, the fierce fighting lasted for nearly half a month, and the fierce resistance of the defenders completely exceeded the expectations of the Tang army. After the initial defeat in the battle out of the city, he could not shrink, so that he completely gave the initiative to the enemy, and sat back and watched the Tang army finally besiege Chang'an, etc., but even so, there were less than 50,000 at most in the city, and only a very small number of elite Guanzhong soldiers and horses, still stuck to the walls of this city, and gave the Tang army, which had besieged the entire Chang'an City and had more than 200,000 troops, to give resolute resistance, until in the end, the Tang army was finally defeated by virtue of the advantage of numbers and tired tactics. The Tang army successfully occupied Chang'an and established its own qualifications and capital to compete in the world. However, the Sui army defending the city was hard, and the Tang army, which was on the attacking side, could not be easy, when the military information from the west, the Western Qin Xue Ju invasion came, among the Tang troops on all roads, the army that could immediately set off to meet the enemy was only those who did not participate in the siege of the city, and were responsible for guarding against the reinforcements of Chang'an City that might appear, because there was no too fierce battle, so there was no need for more rest.

Therefore, when Li Shimin showed his face for the only time in Chang'an City, rescued Li Jing who wanted to be beheaded by Li Yuan from the hands of the knife and axeman, and declared that he was indeed in Chang'an and not somewhere else, Li Shimin did not stay in Chang'an City for long, and immediately led his troops west to meet Xue Ju's Western Qin army. At this time, he may have already known that Chang'an City did not make an inch, and it was his father who wanted to suppress his mind, but the world was unpredictable, but he also failed to think that it was originally because Li Yuan was ashamed in his heart and wanted to compensate him for the appointment of full responsibility for the military affairs of the Western Qin War, but because of the incomparably fierce opponent Xue Ju, he held fiercely for a year. When Li Shimin led his troops west, he was still despised by many generals in the army at the age of 20, but when he returned from pacifying Western Qin a year later, the contemptuous eyes that had appeared in front of his eyes had long since disappeared......

Of course, Li Shimin is not an immortal, he can't predict the future, as a veritable war maniac, at this time he is pondering to himself, what is the origin of this enemy from the west. The eldest grandson Wuji beside him is far inferior to Li Shimin, and he can concentrate on thinking about the enemy he is about to face, his character is already a little narrow, and the misfortune of his childhood has left a deep shadow in his heart, so when the gentle pressure from Li Yuan comes to Li Shimin's head, as a party Li Shimin can also say that it does not matter, but the eldest grandson Wuji's heart has already given birth to a sense of crisis, for Li Shimin, but at the same time, it is also for himself.

Initially, after getting the news of the army, the eldest grandson Wuji abandoned his official position in order to prevent himself from being implicated, coupled with his optimism about Li Shimin, and wanted to rush to Luoyang to join the righteous army, but halfway through he heard the news that Li Shimin had entered Guanzhong, so he changed the direction and marched to Guanzhong, and finally met Li Shimin in the army. This time, Li Shimin went west to face Xue Ju, and the eldest grandson Wuji, who was Li Shimin's left and right hand, naturally had to go with him.

is different from Li Shimin, the pride of the sky, because of the tragic life of his childhood, which was different from ordinary people, the eldest grandson Wuji is very precocious, and he often becomes more vigilant in the interaction between people. Therefore, although Li Shimin was a little dissatisfied with his father's conquest of Chang'an to his brother, he did not care too much. In contrast, the eldest grandson Wuji has seen much farther than Li Shimin, and has always firmly believed that Li Shimin, who is far better than Li Jiancheng, is more suitable for inheriting Li Yuan's family business, even if he does not replace Li Yuan's position in the end, with Li Shimin's talent, is it not enough to rely on his own efforts to become a family of his own? However, at this moment, when the Li family in Taiyuan has the ability to win the world, in the eyes of the eldest grandson Wuji, things have gradually developed to the bad side - although the world is big, no matter how hard Li Shimin works, how can he rely on his own hands to lay down the same vast sky......

If the goal has never been reached, it is fine, but it is clear that he is close but wants to give up with his bare hands, Li Shimin may choose with a smile, but the eldest grandson Wuji will never do this. Moreover, for the eldest grandson Wuji, who has a deep understanding of the dark side of people's hearts, in his opinion, even if Li Shimin really does not fight, will his brother always choose to believe him? For the eldest grandson Wuji, he didn't mind that his hands were stained with anyone's blood except for his own closest relatives. Don't say that there is only one Li Jiancheng, even Li Yuan will be killed to show you.

Eldest Sun Wuji had already made up his mind, but he wasn't sure what Li Shimin thought, and looked at Li Shimin next to him who was also in a contemplative state, how could Eldest Sun Wuji not know that this buddy was full of how to face the enemy he was about to encounter at the moment. For this, the eldest grandson Wuji doesn't know whether to be happy or disappointed, it is true that because he focuses on the war he likes, Li Shimin will never give the enemy any opportunity on the battlefield, but for other things outside the battlefield, Li Shimin pays less attention to it, but it doesn't matter, the eldest grandson Wuji said in his heart, for these, he will make up for Li Shimin. You must follow closely behind this young hero, until you reach the throne that people look up to infinitely...... "Auxiliary, do you say that after learning of our arrival, will Xue Rengao retreat his troops, or will he continue to besiege Fufeng and divide his troops to meet us at the same time?" Li Shimin's voice suddenly sounded in the ears of the eldest Sun Wuji.

"Is this it?" The eldest grandson Wuji pondered for a while, and then replied: "I think, he will retreat, after all, the Fufeng city wall is strong, the garrison is complete, and it is urgent for a while, and our army reinforcements are about to arrive, if Xue Rengao does not retreat, it is very likely that he will be attacked by us inside and outside, Xue Rengao is not a fool, I think he will make a wise choice." The eldest grandson Wuji's analysis is not unreasonable, however, Li Shimin is still frowning, although he has obtained very little information about the father and son of Western Qin, but in his heart, he has already had a general impression of the father and son of Western Qin, Xue Ju is by no means an idle person. And although his son is brutal and easy to kill, he is also brave, an extraordinary person, he should do extraordinary things, Xue Rengao's actions are likely to be unexpected by many people.

Li Shimin said, "It is said that Fufeng originally had a Tang Bi gathering of 100,000 people, and was later broken by Xue Rengao in one fell swoop, and he merged with all of them. The eldest grandson Wuji was very disapproving: "The reason why Xue Rengao was able to win easily was also because Tang Bi had already surrendered to him, if it weren't for this, so that Xue Rengao didn't defend him, how could Xue Rengao defeat him in a battle." Hmph, Xue Rengao is treacherous, just a villain, although he is brave, he is just a horse, and he is not to be afraid. ”

At this time, in the middle of the march, the people gathered around Li Shimin in addition to the eldest grandson Wuji There were many other generals, after hearing from the two of them about Xue Rengao's treacherous sneak attack on Tang Bi, they all clamored, and their words were full of contempt for Xue Rengao, and after seeing the generals such a expression, Li Shimin, who originally wanted to continue to argue with the eldest grandson Wuji and express his own opinions, suddenly had no desire to continue, until after a period of time, the generals gradually quieted down, Li Shimin beckoned the generals and said another word: "Indeed, Xue Rengao is a trustworthy person, and there is nothing to worry about, but his courage and bravery should not be underestimated. Naturally, the generals said yes, and the procession regained its calm and continued its march. The sun moved westward, stretching the shadow of this procession marching towards the sun very long, very long.