The Battle of Red CliffsThe Story of Zhuge Liang Borrowing the East Wind

The Battle of Red Cliffs, a famous battle in Chinese history, took place in the thirteenth year of Jian'an (208), when the allied armies of Sun Quan and Liu Bei defeated Cao Cao's hordes at Red Cliffs. The battle marked the point where the military and political center of China was no longer confined to the Yellow River Valley, and Sun and Liu each captured a portion of Jingzhou, laying the foundation for the Tripartite Alliance.

According to the story of "Romance of the Three Kingdoms," on the eve of the Battle of Red Cliff, Sun and Liu joined forces to fight against Cao Cao, and needed to attack by fire with the help of the southeasterly winds. However, it was the mid-winter season, when the north wind was howling, and it was impossible to have a southeast wind.

So Zhuge Liang volunteered to set up an altar on Nanping Mountain to sacrifice to the wind, and eventually borrowed the southeast wind for three days and three nights to help Zhou Yu defeat Cao Cao's navy. However, this story is not recorded in real history, so it is difficult to determine its authenticity. However, without the help of the east wind, how did Sun and Liu's armies win? In fact, Zhuge Liang was well versed in the art of war and metaphysics, and had studied the state of the weather, and knew the proverb that "the winter solstice is the birth of the sun".

That is to say, on the winter solstice, the temperature will change from cold to warm, which may cause a change in the direction of the wind, and the southeast wind may also appear. Even Cao Cao knows this, as Cheng Yu warned Cao Cao to watch out for the southeast winds, but Cao Cao thought, "The winter solstice is the birth of the sun, and when it comes back, how can there be no southeast winds? How strange!" Cao Cao therefore did not take the southeast wind seriously, leading to his defeat. Therefore, although the Romance of the Three Kingdoms portrays Zhuge Liang as too mysterious, the fact of "borrowing the east wind" is still told according to historical facts.

There is a view that Zhuge Liang used the art of Qi Men Dun Jia, which is a method of selecting favorable times and directions using astronomical calendar and mathematical knowledge to help in decision-making, and is also used in the battlefield. Some people questioned whether Zhuge Liang really knew the art of Qi Men Dun Jia, because he did not calculate the end of the Battle of Lost Street Pavilion. However, there are also opposing views that point out that Zhuge Liang did borrow the east wind, but just did not use advanced methods such as sacrifices. This controversy remains unresolved to this day.