Lieutenant General Prince Imperial Yeong, Yi Un, Crown Prince Uimin, also known as Yi Un, Yi Eun, Lee Eun and Un Yi, was the 28th Head of the Korean Imperial House, an Imperial Japanese Army general and the last crown prince of Korea. In 1910, when the Empire of Korea was annexed by Japan and Emperor Sunjong was forced to abdicate, Yi Un was titled His Highness The Crown Prince of Korea. On 10 June 1926, upon the death of Emperor Sunjong, he became His Highness King Yi of Changdeokgung in Japan. After World War II he was refused entry to Korea, and his Japanese titles were removed by article 14 of the new Constitution of Japan in 1947.
In 1920, he married Princess Masako of Nashimoto, the eldest daughter of Prince Nashimoto Morimasa, on 28 April 1920 at Tokyo.