 Hong Bao was one of the five Assistant Envoys (副使) (along with Zhu Liang, Zhou Man, Yang Zhen, and Zhang Da).Hong Bao, as well as all other Principal and Assistant Envoys except for Zhang Da, had the eunuch rank of Grand Director (太監, "Taijian").Much of what we know about Hong Bao comes from the book written by the interpreter Ma Huan, who served in his squadron during the 7th voyage of Zheng He's fleet.