Map Introduction

Eastern Jin (317–420 AD) was a remnant regime established by Sima Rui in Jiankang (modern Nanjing) after the fall of the Western Jin Dynasty. Its historical evolution can be divided into the following key stages:

I. Establishment and Initial Stability (317–325 AD)

• Fall of Western Jin and Founding of Eastern Jin:

  • In 316 AD, Liu Yao of the Xiongnu captured Chang'an, leading to the collapse of the Western Jin.
  • In 317 AD, supported by northern aristocratic families like Wang Dao and Wang Dun, Sima Rui declared himself emperor in Jiankang, continuing the Jin line, a period historically known as the Eastern Jin.
  • "Wang and Sima, Sharing the World": Powerful aristocratic clans like the Wang clan of Langya held de facto power, while imperial authority remained relatively weak.

• Stabilizing the Jiangnan Region:

  • Sima Rui employed both northern migrant elites (e.g., Wang Dao) and southern local gentry (e.g., Gu Rong), reconciling north-south conflicts.
  • He implemented the "exiled commanderies and counties" system to resettle northern refugees, thereby consolidating his rule.

II. Aristocratic Politics and Northern Expedition Attempts (325–383 AD)

• Aristocratic Dominance and Imperial Struggles:

  • Wang Dun's Rebellion (322–324 AD): Wang Dun rebelled under the pretext of "purifying the emperor's court," exposing tensions between the aristocracy and the throne. Although suppressed, aristocratic power was not fundamentally weakened.
  • Dominance of the Yu and Huan Clans: Figures like Yu Liang, Yu Bing, and later Huan Wen successively controlled the government, using Northern Expeditions to build political capital.

• Three Major Northern Expeditions and Huan Wen's Ascendancy:

  • Zu Ti's Northern Expedition (322 AD): Briefly recovered territories south of the Yellow River but failed due to court suspicion.
  • Expeditions by Yu Liang and Yu Yi: Aimed at reclaiming the Central Plains, with limited success.
  • Huan Wen's Northern Expeditions (354–369 AD):
    • Reached Bashang near Chang'an in 354 AD against Former Qin but retreated due to supply issues.
    • Recaptured Luoyang in 356 AD, but the court failed to consolidate control.
    • Suffered a major defeat at the Battle of Fangtou against Former Yan in 369, halting his campaigns.
  • Huan Wen's Usurpation Ambitions: After 369 AD, Huan Wen attempted to seize the throne unsuccessfully; his son Huan Xuan later continued this ambition.

III. The Battle of Fei River and Brief Resurgence (383–399 AD)

• Battle of Fei River (383 AD):

  • Fu Jian of Former Qin led a massive army south. Eastern Jin, led by Xie An and Xie Xuan, achieved a decisive victory with 80,000 troops of the Beifu Army, causing the collapse of Former Qin.
  • Aftermath: Eastern Jin gained a temporary respite, and the Xie clan's influence reached its peak.

• Xie An's Administration and Internal Conflicts:

  • Xie An pursued a policy of "governing through tranquility" to stabilize the polity, but infighting among the great clans intensified.
  • After Xie An's death in 385 AD, power was monopolized by Sima Daozi and his son Sima Yuanxian, leading to court corruption.

IV. Decline and Replacement by Liu Song (399–420 AD)

• Sun En and Lu Xun Rebellions (399–411 AD):

  • Oppression by the aristocracy sparked uprisings in the Jiangnan region. Although suppressed, these rebellions severely weakened the Eastern Jin state.

• Huan Xuan's Usurpation and the Rise of the Beifu Army:

  • In 403 AD, Huan Xuan forced Emperor An of Jin to abdicate, establishing the short-lived Chu state. He was defeated the following year by Liu Yu.
  • Liu Yu's Ascendancy: The Beifu Army commander Liu Yu rose to prominence, quelling the threats of Huan Xuan and Sun En, and launching successful Northern Expeditions (conquering Southern Yan and Later Qin).

• Fall of Eastern Jin:

  • In 420 AD, Liu Yu deposed Emperor Gong of Jin and founded the Liu Song Dynasty, ending the Eastern Jin and inaugurating the Northern and Southern Dynasties period.

V. Political and Social Characteristics of Eastern Jin

• Aristocratic Politics: Great clans like the Wang, Xie, Yu, and Huan monopolized power, with the throne often dependent on their support.
• North-South Integration: Northern migrant elites and southern gentry evolved from conflict to cooperation, facilitating the southward shift of economic and cultural centers.
• Neo-Daoism and Buddhism: "Pure Conversation" philosophy flourished, while Buddhism (e.g., Huiyuan) integrated with native Chinese culture.
• Southward Economic Shift: Development of the Jiangnan region accelerated, laying the economic foundation for the Southern Dynasties.

Summary

Although a regional regime, Eastern Jin maintained its rule for 103 years through shared governance by great clans and military defense (e.g., the Battle of Fei River). Its aristocratic politics, north-south integration, and cultural developments profoundly influenced subsequent Chinese history.