He was Emperor Xiaozhao's second son but was considered his proper heir because he was born of his wife Empress Yuan.
The scholar Jia Dezhou (賈德冑) had been earlier commissioned to be Gao Bainian's teacher, and while Gao Bainian learned calligraphy, he had once written several instances of the character chi (敕) -- a character that meant "imperial edict," and which only the emperor was supposed to use.
Jia sealed the characters chi that Gao Bainian had written and submitted them to Emperor Wucheng.
Later, during the reign of Emperor Wucheng's son Gao Wei, a number of imperial halls were torn down and rebuilt.
As one of the halls was torn down, a small body wearing an imperial prince robe was found, and it was thought to be Gao Bainian's.