Painting Story:
In medieval era, Song Dynasty(960-1279AD) was the major empire of continental China. It had the best economy development, most cultural diversity as well as the frontiers technology develpment back in China's ancient history.
However, this well developed Song Dynasty was faced invasion from 3 other empires of the north. The strongest one was called Da Jin empire. Its heavy cavalry troops fought most winning battles against Song's defense.
Until 1127AD, Song lost its northern part and reformed to be the Southern Song Dynasty in its remaining southern territory. In this time, 4 superior military generals (included in the painting
) became the mainstay of upholding the defense and revival of the Song Dynasty.
The one most memorized by the Chinese community is Yue Fei (the 2nd person on the left, in light green clothing in the painting). Yue Fei was famous by his creative infantry tricks used in against cavalry battles. His army was mastering the applications and skills of a polearm--the glaives. With his's tricks in battles, Da Jin's heavy cavalrys often be defeated by Song's infantry, as if the prey that run into traps by itself. Since then, heavy cavalrys were no more be dominant in medieval battles.
Yue Fei saved his country and gained outstanding prestige from his battle achievements. Surely, the glaives became the symbols of Yue Fei's army and his leadership. Even nowadays, most Chinese would like to see the glaives (A.K.A Guan Dao) as the most iconic melee weapon in Chinese culture, due to its fascination was originated from Yue Fei's history.
This was painted in Southern Song Dynasty era (1127-1279 AD), recording the appearance of its 4 mainstay generals and their bodyguards. Its now collected by China's National Museum. From this painting, we can see the style of Chinese swords and bows used at that time.
The tragedy of the hero
As Da Jin Empire barely fought any winning battles since Yue Fei's participation and the war campaign between Da Jin and Song had last for more than 10 years, both of these 2 Empires were tired to run warfare furthermore. The emperor of Song (GaoZong)and his diplomatist Qin Hui, started to prioritize diplomacy over military contest in the affairs of Da Jin. When the military forces were not seen as mainstay of the empire, these 4 superior military generals were soon be concerned as potential threads to the throne of Emperor GaoZong in Song's political culture. Yue Fei became the target, becase he was the most capable one among these 4 generals, and faced the "bad drives out good" trend in his career.
Later, under the plot by Emperor GaoZong and Diplomatist Qin Hui, Yue Fei were executed on false charges in the year of 1142 AD. Because he died under injustice, he died when still on an unbeatable hero glory, he died to trigger public disgust to the royal politics, thereby he became a culture hero and established as a deity to be worshiped by the people of Song until today.
The forgetting hero?
It's quite common to see the deity statue of Guan Gong which worshiped by many people in China. This statue can exist in a company office, in a restaurant, in a shop, in residential houses, and many other public spaces.
How this custom came from? A credible answer is, its from the commemorate custom of Yue Fei. Yes, the Guan Gong statue was Yue Fei's back in the time (before 1616 AD). By a historical reason, Yue Fei's head was changed to Guan Gong's.
To explain this, we need to refer the history between Da Jin Empire (1115-1234 AD) and Qing Dynasty (1616-1912 AD). These were 2 regimes established by Jurchen people. When the time comes to Qing Dynasty, Jurchen reformed their ethnic identity, named as Manchu. Manchu people was the ruling class of the whole China in Qing Dynasty(1616-1912 AD), they saw the custom of Yue Fei commemorate could potentially remind people the ideology of Anti-Da Jin (Jurchen), having the risk of use by rebellions for against Manchurian's ruling, thus, Yue Fei deity worship was forced to be converted to the portrait of another battle hero -- Guan Gong (160-220 AD). Since then, people worshiping a deity statue of Yue Fei's figure and dress holding the glaive, with Guan Gong's head on the shoulders, then it became what we can see today.
Taking a close look at the statue, we can see the clothing, armour, and weapon are all in the style of Song Dynasty era, but no signs of Guan Gong's period. Interestly, people rarely realise this 'wrongly styling' deity should be the Yue Fei.