Yangnyeong was the elder brother of Sejong the Great, and an ancestor of Syngman Rhee[citation needed], an independence activist and the first President of South Korea.
On May 1415, he caused a scandal when he had an affair with Chogungjang, the kisaeng of his uncle and former king, Jeongjong.
[4] On 15 February 1417, Yangnyeong secretly brought in Eori, the concubine of Gwak Seon, into the palace.
Yangnyeong criticized his father for punishing him over his affair with Eori, while Taejong himself maintained ten concubines, in direct violation of the Confucian virtue of highest importance: filial piety.
[9] Grand Prince Hyoryeong, Yangnyeong's second brother, had similar feelings about Chungyeong being king, and so he became a monk in a Buddhist temple.