The birthdate and early childhood of North Korean leader Kim Jong-un is shrouded in mystery. It is known that he is the youngest son of Korean military leader Kim Jong Il (also written Jong-il), who, under the communist Worker's Party, had ruled North Korea since 1994; and the grandson of Kim Il-sung, his father's predecessor. Kim Jong Il began to prepare Kim Jong-un for succession to leadership in 2010. Upon his father's death in December 2011, Kim Jong-un assumed power. It is believed that he was in his late 20s at the time. He reportedly counts among his close allies his uncle, Jang Sung-taek, and army political bureau chief Choe Ryong Hae.
Kim Jong-un's mother was opera singer Ko Young-hee, who had two other children and is thought to have campaigned for Kim Jong-un to be his father's successor before her death in 2004. It has been reported that Kim Jong Il indeed took a liking to Kim Jong-un, noting that he saw in the youth a temperament similar to himself. It is also thought that Kim Jong-un may have been educated abroad in Switzerland before attending the Kim Il-sung Military University (named after his grandfather) in the capital of Pyongyang in the mid-2000s.