Northern Yan
Gao Yun (高雲) (died 409), at one time Murong Yun (慕容雲), courtesy name Ziyu (子雨), formally Emperor Huiyi of (Later)/(Northern) Yan ((後)/(北)燕惠懿帝), was an emperor who, depending on the historian's characterization, was either the last emperor of the Later Yan, or the first emperor of its succeeding state Northern Yan. He was a descendant of the royal house of Goguryeo, whose ancestors were captured by Former Yan. He was adopted into the Later Yan imperial house after helping the emperor Murong Bao (Emperor Huimin) put down a rebellion by Murong Bao's son Murong Hui. He became emperor after the people rebelled against the despotic rule of his adoptive uncle Murong Xi (Emperor Zhaowen), and during his reign, he used the title "Heavenly Prince" ("Tian Wang"). In 409, he was assassinated, and after a disturbance, was replaced by his ethnic Han Chinese general Feng Ba (Emperor Wencheng).