Sima Dan

Biography

Family Background and Early Years

Sima Dan, courtesy name Pengzi, was born in 343, the first year of the Jianyuan era. He was the eldest son of Emperor Kang of Jin, Sima Yue, and his mother was Empress Chu Suanzi. Chu Suanzi belonged to the Chu clan of Yangdi in Henan and was a daughter of Grand Tutor Chu Pou. The Chu clan possessed considerable political influence in the middle Eastern Jin period. When Sima Dan was born, his mother was already the reigning emperor's principal empress. He was the first emperor in Chinese history whose mother was already the emperor's principal empress at the time of his birth.

Childhood Accession and the Empress Dowager's Regency

On September 24, 344, the second year of Jianyuan, Emperor Kang appointed Sima Dan Crown Prince. Only two days later, on September 26, Emperor Kang died. On September 27, the two-year-old crown prince ascended the throne and honored his mother Chu Suanzi as Empress Dowager, with Empress Dowager Chu governing as regent. In the tenth month of that year Emperor Kang was buried at Chongping Mausoleum. In the eleventh month, Yu Bing, General of Chariots and Cavalry, died, altering the balance of power at court.

At the beginning of Sima Dan's reign, He Chong, General of Agile Cavalry, assisted the government. He Chong had been decisive in Sima Dan's accession. Before Emperor Kang died, Yu Bing had advocated installing Sima Yu, Prince of Kuaiji, but He Chong strongly opposed the proposal and insisted that Emperor Kang's own son inherit the throne. Sima Dan consequently succeeded. In the first month of 346, the second year of Yonghe, He Chong died. In the second month the court appointed Cai Mo, Grand Master of Splendid Happiness of the Left, concurrently as Minister of Education and Supervisor of the Six Divisions of the Secretariat, to share responsibility for government with Sima Yu, Prince of Kuaiji and General-in-Chief Who Pacifies the Army.

During Empress Dowager Chu's regency, Eastern Jin government was largely conducted by the ministers assisting the throne. Sima Dan was too young to participate in state affairs. Historical sources describe the situation with the expression “governing through the empty imperial robe,” referring to a very young sovereign who occupied the throne while others exercised authority.

Northern Expeditions and the Rise of Huan Wen

In 349, the fifth year of Yonghe, Shi Hu of Later Zhao died and the Central Plains fell into disorder. The Eastern Jin court successively sent Chu Pou, General-in-Chief Who Conquers the North, and Yin Hao to lead Northern Expeditions, but neither achieved success. Chu Pou's expedition failed at Pengcheng, and after retreating he died in shame and anger. Yin Hao launched two campaigns in 352 and 353, the eighth and ninth years of Yonghe. He was first defeated by Former Qin and later suffered a major defeat at the hands of Yao Xiang, after which he was reduced to commoner status.

At the same time, the power of Huan Wen, General Who Conquers the West, grew steadily. In 347, the third year of Yonghe, Huan Wen led an expedition westward, destroyed the Cheng Han regime that had controlled Shu for more than forty years, and recovered Yi Province, restoring Eastern Jin authority in the southwest. In 354, the tenth year of Yonghe, Huan Wen launched a Northern Expedition against Former Qin, entered Guanzhong, advanced as far as Bashang near Chang'an, and then withdrew when his supply system failed. In 356, the twelfth year of Yonghe, Huan Wen campaigned north again, recovered Luoyang, and repaired imperial mausoleums before withdrawing because supplies could not be maintained.

Huan Wen's military campaigns expanded Eastern Jin territory but also greatly increased his personal prestige and military power, creating problems for later Eastern Jin politics. During Sima Dan's reign, the court was largely unable to restrain Huan Wen's expansion of influence. As a historical source states, “Dan's power and authority were weak, and he could not control him.”

Personal Rule and Death

In the first month of 357, the first year of Shengping, Sima Dan, then fifteen years old, underwent the capping ceremony. Empress Dowager Chu returned authority, and Sima Dan began to rule personally. His period of personal rule was short, and the general political structure remained much as it had been under the regency.

On the dingji day of the fifth month in 361, the fifth year of Shengping, Sima Dan died of illness in Xianyang Hall at the age of nineteen by traditional reckoning, or eighteen by full years. In the ninth month he was buried at Yongping Mausoleum, south of Mufu Mountain in the northwest of present-day Jiangning, Jiangsu. Because he had no son, his cousin Sima Pi, eldest son of Emperor Cheng of Jin Sima Yan and Prince of Langya, succeeded him as Emperor Ai of Jin.

Major Activities

Military Expansion and Territorial Recovery

During Sima Dan's reign, the Eastern Jin made several military advances. In 347, the third year of Yonghe, Huan Wen destroyed Cheng Han and recovered Yi Province, one of the most important Eastern Jin military successes of the middle period. In 356, the twelfth year of Yonghe, Huan Wen recovered Luoyang, temporarily extending Eastern Jin influence to the south of the Yellow River. In addition, after the collapse of Later Zhao following Shi Hu's death in 349, Eastern Jin forces launched several Northern Expeditions. Although they failed to recover the Central Plains, they did impose pressure on northern regimes.

Repair of Former Emperors' Mausoleums

In the eleventh month of 356, the twelfth year of Yonghe, Sima Dan sent Che Guan, concurrently Minister of Works and Regular Mounted Attendant, and Yuan Zhen, General of Soaring Dragon, bearing credentials to Luoyang to repair five imperial mausoleums: Gaoyuan Mausoleum of Sima Yi, Junping Mausoleum of Sima Shi, Chongyang Mausoleum of Sima Zhao, Junyang Mausoleum of Sima Yan, and Taiyang Mausoleum of Sima Zhong. The undertaking is recorded in the Book of Jin, and Che Guan also compiled the five-volume Precedents for the Jin Restoration of Imperial Mausoleums. Repairing the former emperors' tombs served as an important statement of Eastern Jin dynastic legitimacy.

Cultural Interests

The Book of Jin says that “Emperor Mu was rather fond of literary learning.” One story relates that after Ran Min deposed the Later Zhao ruler, proclaimed himself emperor, and changed the state name to Wei, Sima Dan had a landscape map of Wei prepared for his viewing. He pierced a mountain ridge on the map with his brush, splitting the ridge in two, and not long afterward Ran Min was indeed destroyed by Former Yan. The story appears in the Spring and Autumn Annals of the Sixteen Kingdoms and in quotations preserved by Cao Xuequan's Gazetteer of Famous Places of the Great Ming Realm. It has a legendary character but reflects the tradition that Sima Dan was interested in maps and literary culture.

Relations with Contemporaries

During Sima Dan's reign he worked successively with major ministers including He Chong, Cai Mo, Sima Yu, and Huan Wen. He Chong had been decisive in securing his accession, while Cai Mo and Sima Yu jointly assisted the government during his childhood. Huan Wen was the most important military commander of the period, and his power expanded rapidly during Sima Dan's reign. In addition, in 350, the sixth year of Yonghe, Cai Mo submitted a memorial requesting retirement. Emperor Mu appeared in audience and sent Palace Attendant Ji Qu and Gentleman at the Yellow Gate Ding Zuan to summon Cai Mo, but Cai Mo sent his Registrar Xie You to reply and refused to obey. The episode illustrates the subtle balance between the emperor and powerful officials.

His reign used the era names Yonghe and Shengping: the era was changed to Yonghe in 345, with Empress Dowager Chu holding court and He Chong as regent; after He Chong died in 346, Cai Mo and Sima Yu, Prince of Kuaiji, took over; in the first month of 357 he assumed the cap of manhood and the empress dowager returned authority, so that he ruled in person; he died at the Xianyang Hall in 361 at the age of nineteen and was buried in the Yongping Mausoleum in the ninth month, his cousin Sima Pi succeeding him.

Personal Relations

• Father: Sima Yue, Emperor Kang of Jin, fourth emperor of the Eastern Jin, posthumous title Emperor Kang
• Mother: Empress Kangxian Chu Suanzi, daughter of Grand Tutor Chu Pou
• Maternal uncle: Chu Xin, who rose to Director of the Palace Library
• Cousin: Sima Pi, Emperor Ai of Jin and sixth emperor of the Eastern Jin; succeeded Sima Dan because the latter had no son
• Cousin: Sima Yi, seventh emperor of the Eastern Jin, later deposed as Duke of Haixi
• Wife: Empress Muzhang He Fani, daughter of He Zhun, Grand Master for Splendid Happiness with Golden Seal and Purple Ribbon
• He Chong: General of Agile Cavalry; decisive in Sima Dan's accession and assisted government until his death in the second year of Yonghe
• Cai Mo: Minister of Education; shared responsibility for government with Sima Yu
• Sima Yu: Prince of Kuaiji and assisting minister; later became Emperor Jianwen of Jin
• Huan Wen: General Who Conquers the West; destroyed Cheng Han, campaigned against Former Qin, recovered Luoyang, and held major military power
• Chu Pou: General-in-Chief Who Conquers the North and Sima Dan's maternal granduncle; died in shame after an unsuccessful Northern Expedition
• Yin Hao: commander of Northern Expeditions; reduced to commoner status after two failed campaigns
• Murong Huang and Murong Jun: rulers of Former Yan who received titles of General-in-Chief from the Eastern Jin
• Zhang Chonghua and Zhang Xuanjing: rulers of Former Liang who received titles of General-in-Chief from the Eastern Jin

Historical Assessment

Eastern Jin and Southern Dynasties

• Cao Pi's ninth Song for the Ancestral Temple of the Jin on the South of the River praised him: “The filial ancestor was early wise, his fair reputation truly excellent. Like the morning sun rising, his brilliance shone from Fusang. His teachings descended from the splendid curtains, his beneficence flowed through the eight directions. Quietly aiding profound principles, he embraced every measure of order. In the west he pacified the usurping Shu; in the north he stabilized the old frontier. His lofty plans carried far, leaving fragrance at court.”
• The Lamentation Text for Emperor Mu of Jin stated: “Reverent, enlightened, cultured, and thoughtful, he was truly respectful and yielding. He was humble as if clothed in plain cloth and forgot all self-importance. His substance was present yet seemed absent; his virtue accorded with divine kings. Beneath the ceremonial crown in the two-columned hall, he entrusted government to his chief ministers. Within he relied on the Duke of Zhou, without on the Grand Duke.”
• Shen Yue's Book of Song states: “At this time the successor ruler was young, the empress dowager exercised rule, and government lay with ministers; therefore earthquakes occurred year after year.”
• Wei Shou's Book of Wei says: “Huan Wen, General Who Pacifies the West, led more than seven thousand of his troops to attack Shu. He submitted a memorial and then departed without awaiting approval. Dan's power and authority were weak, and he could not control him.”

Tang Dynasty

• Fang Xuanling and the other compilers of the Book of Jin wrote: “The Filial Ancestor inherited the throne while still in swaddling clothes and was transformed by his mother's instruction; within and without there were no major disturbances for more than ten years. With the talent of Wuan he opened the frontiers, and with the manner of King Wen his influence reached the Yangzi and Han. Thus, in the words attributed to Confucius, there was nothing to criticize.”
• The Book of Jin also praised him: “Governing through the empty robe, he made great filial piety the principle; following the saintly goodness of his mother, he achieved true reverence. To the west his banners reached the Jade Ramparts, to the north his standards reached the golden walls. The old Bo peoples of Yin were relocated, and all came to submit.”
• The same work states: “Emperor Mu was rather fond of literary learning.”

Ming and Qing Periods

• Jin Chengqi's Brief Histories of the Emperors of Successive Dynasties states: “Emperor Mu inherited the throne while still in swaddling clothes; government came from the empress dowager. He employed Huan Wen, who led an army against Han, pressed forward after victory, and left the Han people without will to resist; they bound themselves and requested surrender. The west was pacified in Shu and Han, and military prestige greatly increased. ... Although the emperor reigned for seventeen years, he died at only nineteen. How could the domineering Huan Wen be relied upon?”

Modern and Contemporary Scholarship

Modern historians generally regard Sima Dan as a child ruler whose government was actually conducted by Empress Dowager Chu and the ministers assisting the throne, leaving him little personal room to govern. Eastern Jin territory expanded during his reign, chiefly because of Huan Wen's military abilities, but the growth of Huan Wen's power also created conditions for later political instability. Sima Dan himself is not associated with major personal political achievements; historical assessments focus mainly on his childhood accession and the delegation of authority to ministers.