Early life and background

Xu Guang was from Dunqiu County in Dong Commandery. He grew up poor and his father Xu Cong (徐聰) only worked as a mere cow doctor. Despite his poor upbringing, he took a liking for studying and reciting literature. As northern China fell into chaos, the Han Zhao general, Shi Le, invaded Dunqiu. His general Wang Yang captured the county, where he took in a 13-year-old Xu Guang as a servant. Xu Guang was ordered to work in Wang Yang's stables, where he would tend to the horses. Xu Guang had no interest in his new work, and instead spent the rest of his time writing poetry and songs on the posts tied to the horses.

Wang Yang eventually found out of Xu Guang's procrastination. Angered, he had him imprisoned and whipped. However, after his release, Wang Yang felt guilty after being informed that Xu Guang had cried all night long. Wang Yang summoned Xu Guang and handed him a brush and paper, which Xu Guang wrote an ode on. Wang Yang was impressed by Xu Guang's talents and rewarded him with robes. He also recommended him to Shi Le, who agreed to appoint him into his administration.

Career under Shi Le

Capture of Wang Jun

Xu Guang followed Shi Le during his campaign to capture Wang Jun in 314. After Wang Jun was captured, Wang Jun scolded Shi Le, "How dare a barbarian like you make a fool of me? What wicked treason is this?" Xu Guang, who was with Shi Le at the time, replied, "You hold the loftiest of offices, and you have powerful soldiers at hand. Yet you sat and watched as the court you served was overthrown, and you did nothing to lend them aid. Now you even want to exalt yourself as the Son of Heaven. Is that not 'wicked treason'? And even though you held an important office, you gave in to perverse greed, inflicting your tyranny on the common people and taxing and harming the loyal and the good. Poison has spread through the whole Yan region, and whose fault is it but yours?" Wang Jun was later brought to Xiangguo (襄國, in modern Xingtai, Hebei) where he was executed.

Envoy to Shao Xu

In 320, a retainer of Wang Jun, Shao Xu was finally captured by Shi Le's nephew, Shi Hu. Shi Le sent Xu Guang as an envoy to the defeated general, telling him in Shi Le's own words, "The nation should be united in order to set aside chaos and return from all directions. Our prestige spreads, but you still cling to Sima Rui and arrogantly defy my king's will. You may think us as inferior, but how is it that is my ruler not fit to rule this land? Why remain ignorant? The world is inhabited by virtuous people, so why must you continue to divide it?」 Shao Xu provided a lengthy explanation for his loyalty to Jin and his reason for defying Shi Le. Shi Le was impressed and had Shao Xu as a respected guest from then on.

Battle of Luoyang

Xu Guang was serving as Records Keeping Army Advisor by 326. That year, Xu Guang ran into trouble with Shi Le. Shi Le summoned him to court one day but Xu Guang could not arrive as he was too drunk. Shi Le thus demoted him to a standard official. On a later occasion, Xu Guang was attending Shi Le when he was displaying an irritated face around him. Shi Le noticed this and was greatly angered. He had Xu Guang and his wife thrown into prison for his behaviour.

Xu Guang was imprisoned for two year until 328, when Shi Le was having his final campaign against Liu Yao of Han Zhao. Shi Le was frustrated by his officials who opposed his decision to personally lead the campaign. With his court against him, he looked towards Xu Guang. Shi Le freed and pardoned him for his past crimes before asking for his advice, which Xu told him, "Liu Yao gained an advantage when he won at Gaohou (高候, north of modern Wenxi County, Shanxi). But rather than advance straight for Xiangguo, he lay siege to Luoyang instead. This shows his lack of ability. Great King, you need only match your valour and cunning against his, and then he will certainly strike his banners and flee in defeat. By this one act, you will settle and bring peace to the realm. You cannot squander this chance." Shi Le was pleased and laughingly said, "It is just as Xu Guang says!"

Xu Guang followed Shi Le during the assault on Luoyang. As Xu had predicted, Shi Le overcame Liu Yao and even captured him in battle. Liu Yao saw Shi Le and told him, "King Shi, have you forgotten the pledge we made together at Zhongmen?" Shi Le sent Xu Guang to tell him, "Today's events were dictated by Heaven's will; what use is there of saying anything further?" The last remaining resistance of Han Zhao's forces were defeated in 329. The following year in 330, Shi Le declared himself Heavenly King and handed out appointments to his officials. Xu Guang in particular became Prefect of the Palace Secretariat and acting Custodian of the Private Library.

Later life, opposing Shi Hu and death

Later that year, Shi Le was worried about his Crown Prince Shi Hong, who was not as militaristic as his father. Xu Guang told him not to worry much about it, comparing the father and son relationship of Shi Le and Shi Hong to that of Emperor Gaozu and Emperor Wen of Han, as the former unified the state through war while the latter established peace in his rule. Shi Le was pleased with the answer but Xu Guang took a step further to bring up about his powerful nephew, Shi Hu. Xu Guang urged Shi Le to reduce his power while increasing Shi Hong's as he feared that Shi Hu would go against Shi Hong in the future. Shi Le took his advice but never acted upon it.

In 331, Shi Le intended to construct a new palace in Ye. However, he was opposed by his Minister of Justice, Xu Xian (續咸). Shi Le was angry and wanted to execute him but Xu Guang intervened and told him that Xu Xian was only giving honest criticism. Shi Le realized this and did not carry out the execution. Instead, he rewarded Xu Xian and delayed the start of the construction.

In 332, Shi Le held a banquet at the beginning of the year. He asked Xu Guang which rulers could he be compared with. Xu Guang told him, "In martial valour, strategy, and resourcefulness, Your Majesty surpasses even Han Gaozu (Liu Bang). There shall never be anyone who can compare with you." Shi Le laughed and told Xu that he had overestimated him. Shi Le believes himself to be lower than Liu Bang but equal to Emperor Guangwu. He concluded his evaluation by condemning the likes of Cao Cao and Sima Yi, who he said "bullied mere orphans and widows and captured the realm through their beguiling." The ministers present kowtowed and chanted "Long live the emperor!"

Some time later, the minister Cheng Xia tried to persuade Shi Le to reduce Shi Hu's power. After he failed, Cheng went to Xu Guang and warned him, "The Prince of Zhongshan (Shi Hu) has long held a grudge against the two of us. I fear that not only is the state in danger, but even our families will suffer misfortune." Thus, Xu Guang took his chance at convincing Shi Le to remove Shi Hu. Coincidentally, when he met with Shi Le, Shi expressed his worries that he would not conquer the south lands before his death. Xu Guang said to him:

Shi Le finally decided to take some action to increase Shi Hong's power. Shi Le allowed him to review petitions from ministers with the Palace Regular Attendant Yan Zhen (嚴震) acting as a supervisor. However, this was still not enough to completely stop Shi Hu. Shi Hu eventually found out about the incident and heavily resented Xu Guang because of it. Shi Le died on the 17th of August in 333. Almost immediately, Shi Hu seized Shi Hong and took over the government. Xu Guang and Cheng Xia were arrested by Shi Hu and brought before the Minister of Justice. Shi Hu granted a general amnesty but left out Xu Guang and Cheng Xia, who were both executed for defying him.

生平

徐光家庭貧苦，父親徐聰是牛醫。徐光自幼好學，有文採。前趙嘉平年間，石勒部將王陽攻打頓丘，俘獲了十三歲的徐光。王陽見他聰明，讓他養馬。徐光常常不喂馬，在栓馬的木柱上寫詩，王陽生氣吊著打徐光。石勒知道後，考察的徐光的能力，任命徐光為記室參軍。徐光常常酗酒，石勒貶他為牙門將。徐光不悅，有怨言，石勒把他下獄兩年多，徐光在獄中寫下了十多萬字的經文註解。石勒的謀士張賓死後，繼任的程遐能力不夠。太和元年（328年），前趙劉曜擊敗石虎，圍攻洛陽，大臣都建議退讓，石勒大怒，于是重新啟用徐光。徐光定策決戰，俘虜劉曜，滅前趙。石勒稱帝，徐光為中書令領秘書監。

石勒問徐光，自己能比作昔日哪位君主，徐光說石勒神謀武略，比漢朝開國君主劉邦更高，僅次于軒轅吧。石勒笑道：「人豈不自知，卿言亦以太過。朕若逢高皇，當北面而事之，與韓彭競鞭而爭先耳。脫遇光武，當並驅于中原，未知鹿死誰手。大丈夫行事當礌礌落落，如日月皎然，終不能如曹孟德、司馬仲達父子，欺他孤兒寡婦，狐媚以取天下也。朕當在二劉之間耳，軒轅豈所擬乎！」

石勒對徐光表示，東晉還在割據江南，李氏占據巴蜀，他擔心後世不會把自己當成真命天子。徐光說，長安、洛陽都在後趙，天下正統毫無疑問。但是心腹之患是權力很大的將軍石虎，勸石勒削弱石虎的權力。石勒臨終前，石虎威迫太子石弘把曾勸石勒除掉自己的程遐和徐光逮捕入獄。建平四年（333年）九月，石勒一死，石弘繼位。石虎下達第一個「詔令」，將右光祿大夫程遐、中書令徐光論罪誅斬。

參考

• 房玄齡《晉書》卷105 石勒載記