在中国古代，皇帝乃是"受天有大命"的真龙天子。因此，他们的孕育、降生都与常人不同，充满了神秘奇异的色彩。传说高祖刘邦，就是其母在大泽旁与神龙交合而生的龙子，其重孙刘彻则是"天彘下凡的龙孙"。（ At ancient China, emperor is the son of the heaven who "has great life according to order of the heaven", and therefore, their breeding and birth are different from that of ordinary people, full of mysterious and fantastic color. There is a legend that Gaozu Liu Bang is son of dragon born at the side of Daze after futunio of his mother and fairy dragon and his great-grandson Liu Che is "grandson of dragon after Tianzhi descending to the world". )