The population of the Three Kingdoms period is only slightly lower than that of the Warring States period, Ge Jianxiong estimated in the "History of Chinese Mouths", the population of the Qin Dynasty was 25 million, then the population of the Warring States Period was about 30 million, and the population of the Three Kingdoms was 22 million to 30 million.
It is reasonable to say that the strength of the Shu Han state is stronger than that of the Yan state and the Korean state, the eastern Wu state is stronger than the Wei state, similar to the Chu state, and the Cao Wei state is stronger than the Zhao state and the Qi state, perhaps similar to the Qin state. However, in the Battle of Yique, the combined forces of Han and Wei were beheaded by 240,000, which was roughly 100,000 han troops and 140,000 Wei troops, and the maximum strength of the Shu Han army was during Zhuge Liang's Northern Expedition, which was 100,000, not higher than that of Korea; the Battle of the Yan Dynasty, the "Chronicle of History" said that the Yan state "raised two armies, the car was 2,000 multiplied", and in the Warring States period, a car followed by about 50 to 100 infantry, and the compromise was calculated by 75 people, then the Yan state's troops in this battle were 150,000, and the maximum strength of this dispatch was also higher than that of Shu Han (the "Warring States Policy" said that the Yan state sent 600,000 troops in this battle, and Lian Po led an army of 130,000 At the same time, the "Records of History" records that the King of Yan "used five to cut one", and the actual strength of Lianpo was 30,000, so the "Warring States Policy" exaggerated the strength of Yan and Zhao's warring forces in roughly four times the proportion).
Comparing the national strength of Eastern Wu with the state of Wei and the state of Chu, there is no doubt that the national strength of Eastern Wu must be higher than that of the state of Wei, and the territory of Eastern Wu includes the land of the former Wuyue, and most of the central and eastern parts of the State of Chu, and what is not included is the area of Hanzhong and Qianzhong County occupied by the State of Qin in the west and the area that extends into the hinterland of the Central Plains in the north, and the territory that is more than the state of Chu is the southeast land to the south of the land of Wuyue, and the area of Lingnan Jiaozhou. However, when Eastern Wu was at its peak, its military strength was only 300,000, and the maximum force dispatched was 200,000 (the Battle of Xincheng launched by Zhuge Ke), compared with the Su Qin Legend Chu State with more than one million armor, even if the strength of the army was half half, it was still half a million, which was higher than Eastern Wu. Similarly, the maximum force used by Wang Qi to lead his army to destroy Chu reached 600,000, which was also higher than that of Cao Wei.
Since the difference in population base is not very large, the Warring States Era can often send hundreds of thousands of people to fight a battle, but the Three Kingdoms Era can not reach such a level, indicating that the main reason for the difference lies in the difference in mobilization ability.
During the Warring States period, the compulsory military system was generally realized, military training was carried out when farmers were idle, farming and production were carried out when farmers were busy, and most of the wars between princely states were selected during the period of agricultural leisure. The Book of Shangjun mentions in the third paragraph of the agricultural war: There are a thousand people engaged in farming and warfare, and if one of them learns "poetry" and "books" and can speak eloquently, then these thousand people will slack off on farming and fighting, and there are a hundred people engaged in farming and fighting, and if one of them engages in handicrafts, then this hundred people will slacken off, the country will be stable by farming and fighting, and the monarch will be honored by farming and fighting. The Book of Shangjun guards the twelfth and also mentions: "The three armies: strong men are one army, strong women are one army, and men and women are one army, and the old and weak men and women are one army.
The above shows that the Qin State attaches great importance to farming warfare and has been raised to the height of the foundation of the country, and the National Council of Qin has formulated such a national policy, which is naturally affected by the increasingly expanding annexation war at that time, and it can be speculated that the Six Kingdoms may also be the same as the Qin State, in order to preserve themselves, they will also take the cultivation war as the foundation of the country accordingly, and other industries, such as handicraft commerce, have suffered a certain degree of restrictions, so most of the princes in the Warring States period have implemented the national military system, often for an important battle, the war potential of a country will be exerted to the extreme.
After the Qin and Han Dynasties, the compulsory military system was changed to a conscription system, professional soldiers began to appear, and the development of industry and commerce also produced a more meticulous social division of labor; at this time, peasants only managed farming, non-commissioned officers only managed to fight wars, and when the world was chaotic, they would vigorously recruit peasants into the army, and even catch Zhuang Ding, but still not in an important battle, a large number of peasants were pulled to the battlefield to fight, and they could not do so.
The most important thing in the Warring States period was farming, so how to stimulate the enthusiasm of the people to cultivate war? Of course, it was rewarded with land and titles, and the Qin state did the best in this regard, and both Shang Martin and Wu Qi suggested that the descendants of the nobles who had no merit be stripped of their fiefs and awarded to those who had merit, but Wu Qi's reforms failed. However, after all, the nobles of the Warring States period were related to the monarch by blood, and the overall interests of the country were consistent, and they would naturally support the great war related to the national fortunes. After the Qin and Han Dynasties, the royal family and nobles still existed, but then there were large clans of scholars, these families are not related to the royal family, wealth and part of the land are in their own hands, and even can use financial resources to annex land and realize the expansion of family power.
The expansion of family power, naturally to raise a group of peasant households, family members, private soldiers (private armed) to work, in the smooth operation of the dynasty, these people in the Shi clan Hao clan all hope to participate in the government through reading, once the dynasty collapses, the first intention of the Shi Clan Hao clan is to preserve their own wealth, so they gather more private soldiers, some of these clans will actively use the family soldiers in their hands, influence to participate in the competition for the masses, trying to divide one side (Cao Cao was helped by Cao Ren and Xiahou Huan in the family when they were fighting together. The Yuan Shao brothers also divided their forces because of their family influence), but there were also more clans that only gathered the population and held a wait-and-see attitude.
Most of the princes of the divided side of the Three Kingdoms period were from the county guards, assassins, and generals in the Han Dynasty system, and in order to gain a firm foothold in the prefectures and counties, they had to obtain the support of the local clans with certain influence and strength, so they would not rob them of their wealth, population, and zhuangding (of course, not all of them, because when the war broke out, sometimes they did not necessarily abide by any rules, and some clan clans would suffer from military disasters, and even suffer because they stood in the wrong team), since the family clan population could not move, There are not many troops that can be mobilized.
In the Three Kingdoms War, some clans formed alliances to protect each other, built forts and forts for defense, moved families in, and even some families directly hid in the mountains and forests. For example, Zhou Yu and Sun Yu attacked Ma and Bao, and captured more than 10,000 people. After Liu Bei was attacked by Lü Bu to take Xuzhou, his family wealth was huge, and there were thousands of servants (slaves) of Lu Zhu, who directly funded Liu Bei's slaves for two thousand, gold and silver currency as military expenses, and let his sister be Liu Bei's wife.
The situation in which the family clan gathered and hid a large number of people was also an important reason for the relatively weak ability to mobilize wars in the Three Kingdoms era, so that the record of winning a hundred people was also worth Chen Shou's calculation in the Romance of the Three Kingdoms.
There is also a third reason is that the war in the Warring States period was roughly an internal war, almost at the doorstep of the occupied land, logistics and transportation were not so difficult, Wang Zhai's 600,000 troops in the battle against Chu were not all troops thrown into battle, or according to the "Book of Shang Jun": the army of strong men, eating enough, sharpening sharp weapons, and waiting for the enemy, while the army of strong women, doing the work of building obstacles, setting traps, destroying bridges and houses, so that the enemy can not use these to attack the city, the old and infirm go to graze cattle, sheep, pigs and horses. Feed livestock as food for strong men and women.