The tattoo on Yue Fei's back is considered by some books since the Ming Dynasty to mean "loyalty to the country". This is a misinformation. The correct thing is to "serve the country with all your loyalty."
After the fall of the Northern Song Dynasty, the country was in crisis. At this critical moment when the country was ruined and the family was destroyed, mother-in-law Yao put the overall situation first and resolutely sent her son to join this just war to protect the family and the country. She was well aware that her son, who had become a disciple of Zhou Dong, was highly skilled in martial arts and was concerned about the safety of the Song Dynasty. She was also afraid that her son would be shaken in his mind in a complicated situation, so before leaving, she stabbed the four words "Serve the country with loyalty" on her son's back. The big characters are intended to remind Yue Fei to always put the interests of the country and the nation first.
Yue Fei's calligraphy "serves the country with all his loyalty"
The original record of these four characters can be found in "History of the Song Dynasty·He Zhu Biography". When Yue Fei was interrogated: "Fei showed it with his bare hands." On the back, there are four characters on the back of Jiu Nirvana, "Serve the country with loyalty", which is deeply understood."
Why Yue Fei's "Serve the country with loyalty" was changed to "Serve the country with loyalty"
It may have something to do with Emperor Gaozong of the Song Dynasty. In recognition of Yue Fei's military exploits in the battle against the Jin soldiers, Emperor Gaozong of the Song Dynasty gave Yue Fei the words "Jing Zhong Yue Fei" and made a flag with "Jing Zhong Yue Fei" written on it. >
Later, folklore conflated the two, and rumors were spread from generation to generation. After the Ming and Qing Dynasties, "serving the country with loyalty" gradually became "serving the country with loyalty"