劉知遠
Liu Chengyou was born in 931 at Yedu (鄴都, in modern Handan, Hebei), at the house of his father Liu Zhiyuan. His father was a trusted officer under the general Shi Jingtang, son-in-law of then-reigning emperor Li Siyuan (Emperor Mingzong) of Later Tang. His mother was Liu Zhiyuan's wife, Lady Li. He had two brothers, Liu Chengxùn (), who was nine years older than him, and Liu Chengxūn (劉承勳, note different tones), who was younger. It is not known whether his brothers were Lady Li's sons. He also had an adoptive brother, Liu Yun, the biological son of his uncle Liu Chong, whom Liu Zhiyuan favored and adopted as a son.