Emperor Cheng of Jin facts for kids

Emperor Cheng of Jin (Chinese: 晉成帝; pinyin: Jìn Chéng Dì; Wade–Giles: Chin Ch'eng-ti), whose personal name was Sima Yan (司馬衍), was an important emperor of the Chinese Eastern Jin dynasty. He was born in December 321 or January 322 and passed away on July 26, 342.

Sima Yan was the oldest son of Emperor Ming of Jin. He became the crown prince, meaning the next in line for the throne, in 325. He became emperor when he was only four years old. During his time as emperor, powerful family members and officials, known as regents, helped him rule. These included his uncle Yu Liang and later Wang Dao. A big challenge during his reign was the Su Jun rebellion, which greatly weakened the Jin dynasty's military.

Becoming Emperor

Sima Yan was the first son of Emperor Ming of Jin and his wife, Empress Yu Wenjun. He was born when his father was still the crown prince. After Emperor Ming became emperor in 323, he made Sima Yan's mother empress. Sima Yan himself was made crown prince in 325.

In the fall of 325, Emperor Ming became very ill. He trusted his young son, Crown Prince Yan, to a group of important officials. These included Wang Dao and his uncle Yu Liang. Emperor Ming likely wanted these officials to work together and keep power balanced. Soon after, Emperor Ming died. Crown Prince Yan, who was only four, then became Emperor Cheng.

Emperor Cheng's Reign

Yu Liang as Regent

At first, several officials shared power. However, Emperor Cheng's mother, Empress Dowager Yu, became the main regent. This made her brother, Yu Liang, the most powerful official. Yu Liang wanted to make laws stricter, which was different from the more relaxed rules under Wang Dao. This upset many officials.

Yu Liang also worried about powerful generals like Tao Kan and Su Jun. He thought they might become too strong. In 326, he even accused a royal family member, Sima Zong, of treason and had him killed. This made many people unhappy with Yu Liang.

The Su Jun Rebellion

In 327, Yu Liang tried to take away Su Jun's military command. He offered Su Jun a new job that didn't involve leading soldiers. Su Jun refused and teamed up with another general, Zu Yue, against Yu Liang. Yu Liang thought he could easily defeat Su Jun and turned down offers of help from other generals.

However, Su Jun quickly captured the capital city, Jiankang, in early 328. He took Emperor Cheng and Empress Dowager Yu hostage. Su Jun's soldiers looted the city, taking possessions from officials and ordinary people. Even the Empress Dowager's servants were taken. Empress Dowager Yu was very upset and worried, and she soon died.

Su Jun set up a new government. Wang Dao was officially in charge, but Su Jun held the real power. Meanwhile, Yu Liang and other generals, including Wen Jiao and Tao Kan, gathered their forces to fight back. Tao Kan was a very skilled general, and his help was crucial.

Su Jun moved Emperor Cheng to a fortress called Shitou, where the emperor and his helpers were kept like prisoners. Wang Dao secretly encouraged other areas to rise against Su Jun. Eventually, Su Jun's own general, Lu Yong, switched sides and joined the anti-Su forces.

The two sides fought for many months. The anti-Su forces had more soldiers but struggled to win. In the fall, during a battle at Shitou, Su Jun fell off his horse and was killed. His brother, Su Yi, tried to continue the fight, but by early 329, Su Jun's forces were defeated.

After the rebellion, Jiankang was badly damaged. Some officials wanted to move the capital, but Wang Dao argued against it. He said Jiankang was important for defending against the northern enemy, Later Zhao. So, the capital stayed in Jiankang. Wang Dao became the main regent, and Yu Liang took a job as a provincial governor. Emperor Cheng, who was now eight, was likely cared for by his grandmother, Lady Xun.

Wang Dao's Regency

Wang Dao largely brought back his earlier, more relaxed way of ruling. This helped to calm things down politically. However, it also led to some corruption and officials not doing their jobs well.

During and after the Su Jun rebellion, the Jin dynasty lost control of many areas in central China to the Later Zhao kingdom. Important cities like Luoyang were lost.

In 336, Emperor Cheng married Empress Du. Both of them were 15 years old.

In 337, a northern leader named Murong Huang, who was supposed to be a Jin ally, declared himself a prince. This meant he was becoming independent from the Jin dynasty.

In 339, Yu Liang wanted to attack Later Zhao to get back lost lands. Wang Dao agreed at first, but other officials disagreed. Emperor Cheng then ordered Yu Liang not to start the war. Wang Dao died later that year. After his death, two new regents took over: He Chong and Yu Liang's younger brother, Yu Bing. Emperor Cheng started making some decisions himself, but these regents still handled most important matters.

Later Years of Reign

After Wang Dao died, Yu Liang again planned to attack Later Zhao. This led to a big attack by Later Zhao's emperor, Shi Hu, in late 339. Later Zhao forces caused a lot of damage to Jin cities north of the Yangtze River. Yu Liang was embarrassed and stopped his plans for a northern campaign. He died in early 340.

Also in 340, Murong Huang officially asked to be called the Prince of Yan. After much discussion among officials, Emperor Cheng himself decided to grant the request.

In spring 341, Empress Du passed away. Emperor Cheng did not choose another empress after her.

Later that year, Emperor Cheng made an important rule. Many people from northern and central China had moved south to escape wars. They were still registered as living in their old hometowns. Emperor Cheng ordered that they now be registered in the areas where they actually lived. This made it easier for local governments to manage their people and resources.

In summer 342, Emperor Cheng became very ill. He had two young sons, Sima Pi and Sima Yi, who were still babies. Yu Bing worried that his family would lose power if a very young emperor took the throne. He convinced Emperor Cheng that the Jin dynasty needed an older, stronger emperor because of the powerful enemy, Later Zhao.

Emperor Cheng agreed and chose his younger brother, Sima Yue, to be his heir instead of his own sons. He died soon after and was succeeded by Sima Yue, who became Emperor Kang.

Era Names

• Xianhe (咸和, Xiánhé): April 15, 326 – February 10, 335
• Xiankang (咸康, Xiánkāng): February 10, 335 – February 11, 342

Family

Emperor Cheng had several family members:

• Empress Chenggong, from the Du clan (321–341), personal name "Lingyang"
• Guiren, from the Zhou clan (died 363)
  • Sima Pi, who later became Emperor Ai (341–365), his first son
  • Sima Yi, who later became Duke Haixi (342–386), his second son
• Unknown
  • Princess Nanping
    • Married Liu Chisong
  • Princess Xunyang
    • Married Wang Yizhi of Taiyuan