Emperor Zhaozong of Tang
Li Yanqing was born in 898, near the end of Tang Dynasty, during the reign of Emperor Zhaozong of Tang. His father, then known as Li Cunshen but who was born with the name of Fu Cun, was an adoptive son of and general under the major late-Tang warlord Li Keyong the Prince of Jin. Li Yanqing was said to be the fourth-born son of Li Cunshen's, but only the identities of two of his older brothers, Li Yanchao () and Li Yanrao (), were recorded in history; he also had at least two younger brothers, Li Yanneng () and Li Yanlin (). (All four of his known brothers would eventually serve as generals.)