Cai Yong
Ma Midi was from Maoling County (茂陵縣), Youfufeng Commandery (右扶風郡), which is located northeast of present-day Xingping, Shaanxi. He was a relative of Ma Rong, an influential Confucian scholar and government official. Ma Midi studied under Ma Rong's tutelage in his younger days and later joined the government service as a Counsellor Remonstrant (諫議大夫). During this time, he and his colleagues Lu Zhi, Cai Yong, Yang Biao (楊彪) and others proofread, edited and annotated the official copies of the Four Books and Five Classics and "Dongguan Han Ji" (東觀漢記) stored in the imperial library. Later, he was reassigned to be a Household Counsellor (光祿大夫).