Format of naming convention in English is under discussion at Wikipedia talk:Naming conventions (Chinese) and Wikipedia talk:Naming conventions (Chinese)/monarchical titles.
Emperor Xiaowu of Jin China (晋孝武帝, 晉孝武帝, Pinyin Jìn Xiàowǔdì, Wade-Giles Chin Hsiao-wu-ti) was an emperor of the Eastern Jin Dynasty (265-420) in China.
During his reign, Jin saw itself survive a major attempt by Former Qin to destroy it, but he would be the last Jinemperor to actually exercise imperial power, as his sons Emperor An and Emperor Gong would be controlled by regents and warlords.
A major issue for the Jin government early in EmperorXiaowu's reign was the continued military pressure exerted by the powerful northern rival, Former Qin.
By 396, EmperorXiaowu was spending so much of his time in drinking and women that he was not seeing his officials on important matters of state on a regular basis.
He became emperor in 419 after his developmentally disabled brother Emperor An was killed by the regent Liu Yu, and during his brief reign, actual power was in Liu Yu's hands.
Sima Dewen was born to EmperorXiaowu of Jin and his concubine Consort Chen Guinü in 386, as their second son, four years after Consort Chen had given birth to their oldest son, Sima Dezong.
Throughout Emperor An's early reign, Sima Dewen received increasingly honorific offices, but had little actual power, as the power was initially in the hands of his uncle, the regent Sima Daozi the Prince of Kuaiji, and later in the hands of Sima Daozi's son Sima Yuanxian.