FACTBOX: Five facts on North Korea's heir apparent

SEOUL (Reuters) - North Korean leader Kim Jong-il, 67, appears to be readying Asia's only communist dynasty for the eventual succession of his youngest known son Kim Jong-un, government officials have said.

The following are five facts about Kim Jong-un:

BIRTH

Jong-un, whose name means "righteous cloud," is thought to have been born in late 1983 or early 1984. His mother Ko Yong-hui, also written as Ko Young-hee, was an ethnic Korean born in Japan who went to the communist state and joined one of its premier dance troupes. Ko also gave birth to the North Korean leader's second son, Kim Jong-chol, in 1981. Ko, who died in 2004, probably from cancer, was either Kim Jong-il's official wife or mistress -- an issue that might weigh on Jong-un's legitimacy.

EDUCATION

Jong-un attended international school in Switzerland, where he learned to speak English and German. Little is known about his education and there are few known photographs of him. He has generally been more elusive than his two elder brothers, who have been spotted traveling outside the North.

SPECULATION ON HIS CHARACTER

Kenji Fujimoto, who served as the personal chef for Kim Jong-il, wrote in a book that Jong-un bears the closest resemblance to his father among the three sons.

Jong-un is also reported to have a ruthless streak and the strongest leadership skills of the three. And, perhaps more importantly, he is thought to be his father's favorite, Fujimoto and other informed sources have been reported as saying.

South Korean media have speculated Kim Jong-un may also suffer diabetes, something thought to have long plagued his father.

CULT OF PERSONALITY

There is none for Jong-un, who has never been mentioned in the North's state media and is virtually unknown to the North's people. By contrast, "Dear Leader" Kim Jong-il, was known for decades and lauded as a revolutionary hero by the North's propaganda machine well before he took over after his father and state founder "Great Leader" Kim Il-sung died in 1994.

PROSPECTS FOR CONTROL

Kim Jong-un will not be able to run the state on his own, given his youth, inexperience and lack of recognition among North Koreans, analysts said.

Kim Jong-il in April promoted Jang Song-thaek, his brother-in-law, to the powerful National Defense Commission, which many analysts took to be an attempt to establish a mechanism for the eventual transfer of power to Jong-un, with Jang as caretaker and kingmaker.

(Reporting by Jon Herskovitz and Jack Kim, Editing by Dean Yates)