Editing Jin dynasty (266–420) (section)

==== Wars with the north ====
{{See also|Battle of Fei River|Liu Yu's Northern Expeditions|Huan Wen's Northern Expeditions}}
In order to recover the lands lost during the fall of the Western Jin, the Eastern Jin dynasty launched several military campaigns against the northern states, such as the [[Huan Wen's Northern Expeditions|expeditions led by Huan Wen]] from 354 to 369. Most notably, in 383, a heavily outnumbered Eastern Jin force inflicted a devastating defeat on the state of Former Qin at the [[Battle of Fei River]]. After this battle, the Former Qin—which had recently unified northern China—began to collapse, and the Jin dynasty recovered the lands south of the [[Yellow River]]. Some of these lands were later lost, but the Jin regained them once more when [[Emperor Wu of Song|Liu Yu]] defeated the northern states in [[Liu Yu's Northern Expeditions|his northern expeditions]] of 409–416.

Despite successes against the northern states like the Battle of Fei River, paranoia in the royal family and a constant disruptions to the throne often caused loss of support for northern campaigns. For example, lack of support by the Jin court was a major cause of Huan Wen's failure to recover the north in his expeditions. Additionally, internal military crises—including the rebellions of generals [[Wang Dun]] and [[Su Jun]], but also lesser ''fangzhen'' ({{lang|zh|方鎮}} 'military command') revolts—plagued the Eastern Jin throughout its 104-year existence.