Terrain occupies an important position in war, and it can be said that it is difficult to truly understand war without understanding the impact of terrain on war.
Before coming to Wuhan, I lived in Xiangzhou for eight years, and in the long history of our country, Xiangzhou has a more famous name, called Xiangyang. Xiangyang has always been a strategic place, known as the throat of the world.
The reason why Xiangyang is called the throat of the world is because the terrain of our country, from west to east, gradually changes from mountains and rivers to plains. With the Qinling Huai River as the rough dividing line, it seems to stretch for thousands of miles, but due to the barrier of natural terrain, since the ancient northern regime wants to go south, the southern regime wants to go north, basically only three large passages can be walked, in most of the time, located in the middle of the South (Yang) Xiang (Yang) Pass belongs to the most important hub, connecting the other two channels, so there have been frequent wars.
Regarding the three passages from north to south, for the sake of ease of understanding, we can use the three kingdoms era wars as examples, namely the Hefei Shouchun line in the east, the Jingxiang in the middle road, and the Chuanlong in the west. Most of the great wars after the establishment of the Three Kingdoms took place here (except Yiling), starting from the east, it is reasonable to say that the Huai River Plain in the east is smooth and developed in road traffic, which should be the most conducive to the attack of the army, but this river is longitudinal, full of lakes and swamps, and there are natural dangers of the Yangtze River, and the cavalry in the north is not satisfied with the water and soil here, and they are often helpless. After a long period of war practice, people found that using the rich river network system here, several relatively easy land and water passages could be found, which could go straight down to Jiangdong. Therefore, if the southern regime wants to stick to it, it is far from enough to rely on the natural dangers of the Yangtze River, and the ancients must guard the River, and only by firmly holding the strategic points on the north bank of the Yangtze River (Yangzhou area), so that the North cannot control the river surface through manpower superiority shipbuilding, can we really sit back and relax.
Although Sun Quan was not as brave as his father and brother, his mind to make meritorious achievements had never been broken, and Eastern Wu, as one of the few in history, failed to control Huainan, but it had a long-standing regime, because of the repeated tug-of-war between Eastern Wu and Cao Wei in the Huainan area, making the land deserted, resulting in a large area of no man's land, and it was difficult for both sides to effectively control.
Every time the Wei army marched south, it could only build ships before the tributaries of the Huai River, whirlpool water or Yingshui, and then wait for the spring and summer water to rise and take the Huai River into the Yangtze River. This not only took time and effort, but also the ships built on these tributaries could not be too large, so that it was completely impossible for the water army of Eastern Wu to fight the enemy on the Yangtze River. Unable to annihilate the Eastern Wu water army, the main force could not cross the river, and could only send elites to cross the river in small boats to sneak attack. If the army forcibly crosses the river, the logistical supply cannot be guaranteed, and there is no doubt that it will be defeated.
In the great war that occurred in the east, Sun Quan first attacked Hefei for a long time, achieving Zhang Liao's prestige. (Zhang Liao left a deep psychological shadow on Sun Quan, and later Zhang Liao took the illness to accompany Cao Pi on the southern expedition, and Sun Quan specifically instructed the front-line generals to "although Zhang Liao is ill, he should not be cautious".) Cao Cao crossed chao lake in four directions and lamented that having a son should be like Sun Zhongmou. After Wei Wu's death, Emperor Wen Cao Pi personally marched twice, the first time, the dragon ship he personally rode on was almost blown to the south bank by the strong wind, which made the "subordinates break their guts". The second time, he led more than 100,000 people to watch the troops at Guangling Linjiang, claiming to teach the generals a strategy in Linjiang. And with great interest, it is a poem, and there are clouds in the poem: who clouds and rivers are wide, and a reed can sail. However, writing poetry is after all writing poetry, the so-called reed can be navigated, in fact, it is a cold winter, the river surface ice is very much, Cao Pi had to retreat, leaving a famous saying "solid heaven so separated from the north and south also." After that, Eastern Wu also crossed the river for many years to harass, forcing Cao Wei to retreat the defensive line and abandon the old city of Hefei, but he was unable to advance north.
The jingxiang area of the middle road is located between the Qinling Mountains and the Funiu Mountain of dabie Mountain, and the mountains on the left and right are longitudinal, but the terrain here is relatively gentle to form a basin, which becomes a natural pass. From the north, it can go straight to Luoyang Xuchang, and the map is zhongyuan Dingding (historically, the Chu state went north from this road to ask the King of Zhou). From the south, it can go hand in hand with land and water, look at the south of Jiangxi, and go down the Yangtze River to Jiankang.
After the Battle of Chibi, the three families of Wei Shu and Wu divided Jingzhou together, and the State of Shu launched the Northern Expedition by Guan Yu in accordance with the strategy of Longzhong, breaking through Fancheng for a time, besieging Xiangyang, flooding the Seventh Army, and Wei Zhen huaxia almost broke Cao Wei's defense line, and the State of Wei even considered moving the capital to avoid the front. As a result, he was secretly attacked by Eastern Wu in Jiangling, and his achievements were defeated. After that, Cao Wei and Eastern Wu divided Jingzhou equally, and Lu Xun and Zhuge Jin made several northward advances, but with little success. (Zhuge Jin's ability is really not good, his existence is to set off Lu Xun's appearance of great composure and self-confidence every time he withdraws his troops)
The west is steep with the Qinling Mountains, which makes Hanzhong particularly important. From Chang'an, over the majestic mountains into Hanzhong, there are several Shu Roads winding between the Qinling Mountains and Daba Mountain, and the Sichuan Basin lies behind the barrier of nature. This road is too steep, easy to defend and difficult to forge ahead.
Shu Han lived in a corner of Sichuan and enjoyed the Tianfu, but it was unbearable. Zhuge Liang composed the "Table of Teachers", counted out Qishan, although he did not have great achievements, but achieved the strategic advantage of attacking instead of defending, and people evaluated the so-called "cool and yong do not dissolve the armor, and China does not release the saddle." During this period, Cao Zhen launched a counterattack, which was blocked by heavy rain, and the only highlight of this crusade against the Shu state was Sima Yi, and the "Records of Emperor Xuan of the Book of Jin" recorded the strange and magical feats of Sima Xuanwang in more than ten characters, "The emperor opened the road from the western city of Shushan, marched on land and water, and traced the (Han River) upwards, as for Shu Ren, pull up his Xinfeng County." Junci Dankou, in case of rain, class division".
The reason why it is strange is because Shu Ren is today's Yunyang County, Chongqing City, and Sima Yi attacked Hanzhong from Xicheng to hanshui, turning over the map to see, this is obviously two unrelated directions, there is a Gap Mountain in the middle, more than a thousand years later, if you want to go from Xicheng (Shaanxi Ankang) to Chongqing to chongqing, you have to bypass the entire Daba Mountain, which is a road that no one has ever walked in history. King Xuan was indeed a genius, and Daba Mountain was so dangerous that it was like a land boat, coming and going freely, turning over the past and back. Then there was the magic thing, because the Shu Kingdom did not have two places, Xinfeng County and Dankou, and Xinfeng County in the Han Dynasty was near Chang'an in Guanzhong. Well, in this way, Sima Xuan, the king of Shu, crossed the entire Daba Mountain, reached the vicinity of Chongqing, conquered the Wei state of Xinfeng County near Chang'an, and then crossed the Daba Mountain and returned. It's not just a flip, it's a crossing. As for Dankou, it is even more unknown in which dimension, and no historian in the past can verify where it is. I have to sigh that "The Book of Jin" is indeed a work of magical historicism.
Nowadays, the Internet is popular to overturn the case, and some people take the "Romance of the Three Kingdoms" in the "Romance of the Three Kingdoms" that "Ran Liangcai, Yu Zhirong is long, the strange plot is short, and the work of the people is better than the general.". To prove that Zhuge Liang's military ability is actually average, in fact, a little patience to continue to read later, Chen Shou said in the next paragraph, "And the enemy, or the value of the people, plus the multitude, attack and defend the alien body, so although the crowd has been moving for many years, it has not been able to be restrained." He also said, "Gai Heaven has a destiny, and we cannot argue with wisdom." "Yes, after all, the Destiny of Heaven has returned, the world belongs to Jin, the old Yin and Yang Master Chen Shou belongs to the historian of the Jin Dynasty, many things can not be written too clearly, can only rely on the reader to taste between the lines." The Romance of the Three Kingdoms contains many similar and interesting details, such as biographies of people about the change of Gao Pingling, but these are all digressions and will not be elaborated.
The author of this article: Chu Xidao, "This is the war" to join the author, without the author himself and "this is the war" permission, any media, self-media shall not be reprinted, violators will be investigated for legal responsibility, readers welcome to forward.