First of all, we must explain a problem, Qin Shi Huang integrated the six kingdoms, and the military strength in his hands did exceed one million, but what is the use of this?
For him, it was only a change in the numbers on his hands, and for the soldiers, it was just a change of emperor, and the town was still guarding wherever it was.
Moreover, the Great Qin Empire's rule over the six Kwantung kingdoms was not very strong in itself, which undoubtedly meant that some elite soldiers had to be divided to manage the local army. While their own troops were still fighting with others, Zhao Tuo and Ren Hu went south with the Qin army, which claimed to be 500,000, and attacked the Baiyue tribe in five ways; Meng Tian led 300,000 troops to attack the Xiongnu in the north and seize Hetao, the so-called million army, distributed in a large empire of three million square kilometers, on average, how many people per square kilometer?
Moreover, Qin Shi Huang had just unified the six kingdoms, the military power politics was still unstable, the morale of the generals and soldiers was low, and most of them did not have the heart to fight at all.
As more and more rebels increased, the Rulers of the Qin Dynasty finally realized that it was not possible to continue like this, so they asked Zhang Handan to take 200,000 regular troops to suppress the uprising. At the beginning, the troops led by Zhang Handan did eliminate many rebel armies, but the result was often that the rebel army here had just been suppressed, and the rebel army there had sprung up again, making Zhang Handan annoyed and tired. Qin Shi Huang realized that the situation was urgent, so he pushed the prisoners to join the rebellion as a town rebel.
Third, although Qin Shi Huang transferred all the armies in the city to fight or fight on the frontier. However, according to historical documents, any uprising can quickly attract hundreds of thousands of troops, which can be deduced that the number of young and middle-aged people in the Qin Dynasty at that time was at least more than 1.5 million, which is also more in line with the population of the Qin Dynasty (about 30 million).
According to the Qin Dynasty law's system of serving young men twice before and after, it can be known that if the young and middle-aged people in the country at that time had completed the conscription, conciliation and conscription stipulated by the state, they would generally not be required to do anything.
In the absence of major military activities, the Qin Dynasty government would not maintain too many troops, first, there were too many people to facilitate management, and the other was to reduce financial pressure. Fighting a war requires money, the army's expenditure has accounted for more than half of the national treasury, even if the Qin state is rich, it does not dare to build it, so there are a considerable number of soldiers who have received strict training idle, whenever there is an uprising, the imperial court has not yet had time to recruit troops, these places have been occupied by the rebels, and the army trained by itself in turn wants to attack itself.
In the autumn of the first year of Qin II, Chen Sheng and Wu Guang launched an uprising of more than 900 soldiers in Dazexiang, which opened the prelude to the overthrow of the Qin Dynasty. From the beginning of the Dazexiang uprising to the response of various places, the Qin Dynasty did not pay attention to this "chaotic party", but only let the local county guards eliminate it on their own.
It was not until the uprising swept through the land of Shandong that the Qin court felt a crisis.
As mentioned earlier, the idle army had been occupied by the rebels, and the Qin Dynasty government naturally could not draw personnel from these places to serve. As for the other armies? The army led by Meng Tian was defending the Xiongnu in the northwest; and the 500,000 expeditionary army led by Ren Hu and Zhao Tuo was attacking South Vietnam, and Qin Shi Huang's death order was to stay still (to prevent the southern counties that had just been captured at that time from defecting), so there was a serious shortage of soldiers and horses that the Qin Dynasty could use to suppress the uprising at that time, which made the Shaofu Zhang Handan temporarily fight with a 200,000 "army" of 200,000 prisoners from Lishan and Prisoners from Xianyang.
Although it was a temporary patchwork team, Zhang Handan still annihilated Xiang Liang with this unit, and the combat effectiveness was evident from this.
Why does this army have such a strong fighting force?
The prisoner's mentality is a key factor, because they know that only meritorious service can wash away the shame in their bodies. According to the law of the Qin State at that time to reward military merit, as long as soldiers made military merits on the battlefield, they could get knighthoods, be exempted from hard labor, and be granted land; they could also use military merits to exempt relatives who had major crimes in their families, so soldiers desperately killed the enemy to win battle merits.
Moreover, there are also many prisoners who are strong in martial arts, brave and courageous. For example, in the last years of the Qin Dynasty, Yingbu also went to Lishan to build the Mausoleum of the First Qin Emperor because of his guilt, but in the riots, he followed the Xiang clan against Qin, repeatedly made battle achievements, and stood out from the crowd, from an oppressed low-level prisoner to become the mighty King of Jiujiang.
After the uprising of Chen Sheng and Wu Guang, the remnants of the Six Kingdoms also rose up to restore the country, and were widely supported by the local people, and the Qin army scattered in various places could be described as geographical advantages and losses, and suffered a devastating blow. Chen Shengbu briefed Zhou Wen at Hangu Pass, and the Qin Dynasty had to temporarily enlist Lishan to serve as an army of prisoners, led by Zhang Handan, and after several twists and turns, finally suppressed this group of rebels in DazeXiang.
It can be seen from this that Qin Shi Huang's "first army system" is still very unique and effective, such a temporary army composed of prisoners, soldiers desperately kill the enemy regardless of life and death, domineering side leakage on the battlefield, before the war has already won half, among which there are unexplored talents, how can such a death squad-like army not be powerful?