慕容儁
In spring 350, Murong Jun launched the attack, and they quickly captured the important city of Jicheng (薊城, in modern Beijing). Murong Jun then moved the capital from Longcheng (龍城, in modern Jinzhou, Liaoning) to Jicheng. In short order, the entire Youzhou (幽州, modern Beijing, Tianjin, and northern Hebei) became Former Yan possession. He then continued to march south, but temporarily halted his advances after nearly being defeated by the Later Zhao general Lubo Zao (鹿勃早).