Emperor Zhaozong of Tang
It is not known when or where Lu Cheng was born, although it was said that he was from a prominent aristocratic family. Both his grandfather Lu Yi (盧懿) and father Lu Yun (盧蘊) were said to be prominent officials, although their titles were not stated in historical accounts. Lu Cheng himself passed the imperial examinations in the "Jinshi" class late in "Tianfu" era (901-904) of Emperor Zhaozong of Tang. The chancellor Cui Yin, who was then also the acting director of the salt and iron monopolies, made Lu one of his surveyors.