When Sima Guang was young, the story of smashing the cylinder in order to save his companions who fell into the water had long been widely circulated. Sima Guang was 20 years old and was later appointed as Feng LiLang.
Although he was born in an official family, Sima Guang liked simple things and did not pursue luxury. Once, the emperor invited his courtiers to a banquet, and according to the custom, everyone wore gorgeous clothes and flowers to the banquet, except for the young Sima Guang, who did not wear flowers. Later, some people said that this was the emperor's reward, and it was not possible not to wear it, so he reluctantly planted the flower on his head. When serving as the general judge of The Merger Prefecture, the Western Xia people often invaded the Merger Prefecture, causing the local chickens and dogs to be restless, and the people's lives were uneasy, which was a major disaster for the local area.
Therefore, Sima Guang suggested to his superior Pang Zhi: "We might as well build two castles to contain the Western Xia people." Pang Zhi followed his advice and sent his subordinate Guo En to do it. Guo En, a reckless man, led his troops across the river overnight, and because he did not pay attention to the fortification, he was quickly discovered and destroyed by the enemy, and his superior Pang Yuan was deposed from his official position because of this. Sima Guang, the proposer of this proposal, was too unwilling to go, and three times wrote to the imperial court to blame himself and asked for resignation, but he was not allowed. After Pang's death, Sima Guang worshipped Pang's wife as a righteous mother and took care of Pang's son like a family. Sima Guang treated his friends so righteously, and of course treated his own family very filial piety, treating his brother Sima Dan, who was nearly eighty years old, with respect like a father, and even more like taking care of a baby. When he was an official, Sima Guang was just and honest, and even if he was an opponent with different ideas, he admired him very much.
Later, because of the political turmoil, Sima Guang withdrew from the official field and began to devote himself to writing history books, so there was the "Zizhi Tongjian". In chronological order, this book explains important figures and stories in history, and expounds many principles for governing the country and employing people.