 {| cellpadding=3px cellspacing=0px bgcolor=#f7f8ff style="float:right; border:2px solid; margin:5px;" !align=center style="background:#ccf; border-bottom:2px solid" colspan=2|emperor cheng of jin (ææå¸) |- |align=right style="border-top:1px solid"|family name:||style="border-top:1px solid"|sima (å¸é¦¬; sÄ«mÇ) |- |align=right style="border-top:1px solid"|given name:||style="border-top:1px solid"|yan (è¡, yÇn) |- |align=right style="border-top:1px solid"|temple name:||style="border-top:1px solid"|xianzong (é¡¯å®, xiÇnzÅng) |- |align=right style="border-top:1px solid"|posthumous name:||style="border-top:1px solid"|cheng (æ, chÃ©ng),literary meaning: "successful" |- |} emperor cheng of jin (; 321 â 26 july 342), personal name sima yan (å¸é¦¬è¡), courtesy name shigen (ä¸æ ¹), was an emperor of the eastern jin dynasty (265-420). he was the eldest son of emperor ming and became the crown prince on april 1, 325. during his reign, the administration was largely dominated by a succession of regentsâinitially his uncle yu liang, then wang dao, then the joint administration of he chong (ä½å) and another uncle yu bing (åº¾å°). he became emperor at age four, and soon after his accession to the throne, the disastrous rebellion of su jun weakened jin forces for decades. ==family background== sima yan was born as the oldest son of emperor ming of jin, who was crown prince at that time, by his wife crown princess yu wenjun, in 321. after emperor ming took the throne in 323 following the death of his father emperor yuan, he created crown princess yu empress, but did not immediately create prince yan crown prince, until 325. in fall 325, emperor ming grew ill. he entrusted the four-year-old crown prince yan to a group of high-level officials, including sima yang (å¸é¦¬ç¾) the prince of xiyang, wang dao, bian kun (åå£¼), chi jian (éé), lu ye (é¸ç±), wen jiao, and empress yu's brother yu liang, perhaps intending that they lead by group with a balance of power. he died soon thereafter. crown prince yan took the throne as emperor cheng. ==reign== === yu liang's regency === initially, the officials were in charge together, but as empress dowager yu became regent, yu liang became effectively the most powerful official in the administration. he changed from the lenient policies of wang (who was prime minister during emperor ming's reign) to stricter applications of laws and regulations, which offended the officials accustomed to wang's lenience. further, he became apprehensive of the generals [[tao 
321_births 4th-century_Chinese_monarchs Emperors_from_Nanjing Jin_dynasty_(265a420)_emperors