Format of naming convention in English is under discussion at Wikipedia talk:Naming conventions (Chinese) and Wikipedia talk:Naming conventions (Chinese)/monarchical titles.
Emperor Kang of Jin China (321 or 322-November 17, 344) was an emperor of the Eastern Jin Dynasty (265-420). He was a son of Emperor Ming and younger brother (from the same mother) of Emperor Cheng.
Xu Suanzi (褚蒜子) (323 or 324-July 5, 384, marriage before accession of Emperor Kang), revered Queen Xian (献皇后, literary meaning: the dedicated or enlightened queen)
For instance both Han Wudi and JinKangdi[?] picked Jianyuan as their motto.
Thus 344 AD was the second year of Jianyuan of Jin Dynasty (or of JinKangdi) whereas 139 BC was the second year of Jianyuan of Han Dynasty (or of Han Wudi).
Before the Republic of China was established, only the emperor can declare a nian hao which was supposed to be unique in the country; hence it is a symbol of imperial power.
The Jin Dynasty (26185; pinyin j?n, 265-420) followed the Three Kingdoms and preceded the Southern and Northern Dynasties in China.
Meanwhile remnants of the Jin court fled from the north to the south and reestablished the Jin court at Jiankang, which was located south-eastward of Luoyang and Chang'an and near modern-day Nanjing, under Prince of Longya.
Battle of Fei turned out to be a victory of Jin under a short-lived cooperation of Huan Chong, brother of Huan Wen and the Prime Minister (or Imperial Secretariat) Xie An.