Jeongjong, the second ruler of the Joseon dynasty, was born in 1357 as the second son of Yi Seong-gye (later King Taejo) and his first wife, Lady Han. A competent military officer, Jeongjong participated in battles alongside his father during the decline of the Goryeo dynasty. Upon his father's ascension to the throne in 1392, Jeongjong was made a prince.

King Taejo had two wives, with Jeongjong being one of the six sons from his first marriage. Taejo's favoritism towards his youngest son from his second wife, Lady Gang, and the backing of this son by Chief State Councillor Jeong Do-jeon, created resentment among Taejo's other sons.

The familial tensions culminated in 1398 when Taejo's fifth son, Yi Bang-won (later King Taejong), led a coup that resulted in the deaths of his two younger half-brothers and Jeong Do-jeon. After the coup, Yi Bang-won initially supported his elder brother Yi Bang-gwa (Jeongjong) for the throne. Taejo, distraught by the bloodshed, abdicated, leading to Jeongjong's ascension as the second ruler of Joseon.

During Jeongjong's reign, he moved the government back to Gaegyeong, the old Goryeo capital. In 1400, another conflict arose between Yi Bang-won and Jeongjong's elder brother, Yi Bang-gan. After Yi Bang-won's forces defeated Yi Bang-gan, who was subsequently exiled, Jeongjong, recognizing his limited power and Yi Bang-won's influence, appointed Yi Bang-won as crown prince and abdicated. Despite his reign being marked by family strife and bloodshed, Jeongjong was an able administrator.