Yi Gu

Yi Ku (Korean: 이구; December 29, 1931 – July 16, 2005) was a member of the Korean royal family and held the title of head of the House of Yi from 1970 until his death in 2005. He was a grandson of Emperor Gojong of the Joseon dynasty.

Born in Kitashirakawa Palace, located in Kioicho, Kojimachiku, Tokyo, Japan, Yi Ku's parents were Crown Prince Yi Un of Korea and Yi Bangja. His birthplace is now known as the Akasaka Prince Classic House, formerly part of the Akasaka Prince Hotel. He received education at the Gakushuin Peers' School in Tokyo. Later, he attended Centre College in Danville, Kentucky, and studied architecture at the Massachusetts Institute of Technology (MIT) in the United States.

In his professional career, Yi Ku worked as an architect with I.M. Pei & Associates in Manhattan, New York, from 1959 to 1964. He was declared stateless by Japan in 1947, but acquired United States citizenship in 1959 and South Korean citizenship in 1964.

Yi Ku married Julia Mullock on October 25, 1959, at St. George's Church in New York. Mullock was born in 1927 and died in 2017. The couple adopted a daughter named Eugenia Unsuk.

Following the fall of President Syngman Rhee's government in South Korea, Yi Ku returned to Korea in 1963 with the support of the new president, Park Chung Hee. He moved into the New Building of Nakseonjae Hall at Changdeokgung Palace with his mother and wife. He took on roles as a lecturer on architecture at Seoul National University and Yonsei University. Additionally, he managed his own airline, Shinhan, which declared bankruptcy in 1979. Subsequently, Yi Ku traveled to Japan to seek economic opportunities.

In 1982, Yi Ku was compelled by his family to divorce Mullock due to her sterility. His mother passed away in 1989. During the later years of his life, Yi Ku lived with Japanese astrologer Kinuko Arita. In November 1996, he decided to reside permanently in Korea.

Yi Ku's health declined, and he died of a heart attack at age seventy-five on July 16, 2005, at the Akasaka Prince Hotel in Tokyo, Japan, which was the former residence of his parents. His funeral took place on July 24, 2005. The Jeonju Lee Royal Family Association posthumously bestowed upon him the title "Prince Imperial Hoeun" (회은황세손).

He was buried at the Hoeinwon Royal Tomb near his parents' graves. Yi Ku did not have an heir. Before his death, he considered adopting an heir from the royal family line. His first cousin once removed, Yi Won, was selected as his successor following Yi Ku's approval and subsequent formal adoption in July 2005. Yi Ku met with the chairman of the association, Lee Hwan-ey, shortly before his death, and signed documents officially adopting Yi Won as his heir. The Jeonju Lee Royal Family Association officially recognized Yi Won as the successor on July 22, 2005, two days after Yi Ku's death.

No additional personal or career details beyond these are documented in the provided sources.