It can be said that as long as China is a city with a bit of history, it can be said that it is an ancient "place where soldiers must fight". However, this "place where soldiers and families must contend" is also divided into grades according to the hard indicators of urban population, size, and strategy, such as Xiangyang, Xuzhou, Hanzhong, and other places that are familiar to everyone.
So, how did the "place where soldiers must fight" come about?
Cities are not naturally generated, but artificially built the day after tomorrow. In primitive society, people built their own places of residence according to the geographical advantages and climatic conditions of the region, and tribes and villages came into being. After the development of history, human material life has become increasingly rich, productive forces have been improved, and people have a higher pursuit of living conditions, so there has been a transformation from villages to townships. From the pre-Qin to the feudal society, the country tended to be unified, but the scope of activities became larger and larger, which also contributed to the flow of population, and the inevitable result of population flow was the formation of large cities.
But the functions of cities between cities are indeed not the same. Like Luoyang and Chang'an, they are positioned as the political centers of the dynasty, like Bianguan Datong and Jiayuguan are positioned as border passes, and like Suzhou, Yangzhou, and Chengdu, these are economic cities.
However, the hidden dangers of ancient wars often do not only originate from the outside, but mostly from the inside, especially at the end of the dynasty, there are often chaos in the world and warlords, so in addition to the internal border fortresses, the strategic fulcrum in the region was born inside. For example, Xuzhou in the north-south junction belt, whether it is the northern expedition in the south or the southern expedition in the north, Xuzhou, which has a flat terrain and interdependent mountains and rivers, will become an inevitable competition between soldiers and families, so it has formed the theory of a military town within the country.
What are the "places where soldiers must fight" and soldiers are fighting for?
The object of contention between soldiers and families is nothing more than two points: one is the money and food of soldiers and horses, and the other is the transportation strategy.
Since it is a scramble, then it means that the war is still continuing, in ancient wars, the most basic thing to support the victory or defeat of the war is to have enough soldiers, who has a huge army and money and grain, then the balance of victory in the war will fall to which side, so the place where the soldiers must first fight must be the area with large population density, where there is a lot of grain production, which can supply the consumption of the huge war, just like the Jianghuai region where Xuzhou is located, and the Jianghan Plain where Xiangyang is located, are all large production areas and population concentration areas, how can they surrender to the enemy?
In addition to the money and food of soldiers and horses, high-level strategic places must also be uniquely located, accessible in all directions, and have great military strategic value. Just like Jinzhou, whoever takes Jinzhou will grasp the initiative to attack Guannei or Guanwai, for example, if hanzhong is taken, it will pinch the lifeline between Sichuan and Guanlong, which is examined from the level of grand strategy.