Kim Jong-un is believed to have been designated the next leader of North Korea, succeeding his father, the "Dear Leader" Kim Jong-il. The BBC News website and BBC Monitoring profile this elusive young man.
The only known image of Kim Jong-un shows him as a young boy
Kim Jong-un is youngest son of Kim Jong-il and his late third wife Ko Yong-hui.
Born in 1983 or early 1984, the young Kim was initially not thought to be in the frame to take up his father's mantle.
Analysts focused their attention on his half-brother Kim Jong-nam and older full brother Kim Jong-chol.
But speculation that he was being groomed to succeed his father picked up in January 2009, after a report in South Korea's Yonhap news agency suggested that Kim Jong-il had picked him as heir.
North Korea watchers also took his reported appointment to the powerful National Defence Commission as a possible signal that he was being moved into a leadership position.
The defence commission is North Korea's most important government body, and Kim Jong-il rules the country in his capacity as the commission's chairman.
On 2 June 2009, Seoul's intelligence agency reportedly briefed legislators that North Korean officials had been ordered to support the choice of Kim Jong-un as the next leader.
However there has also been much speculation that the man being lined up as the real "power behind the throne" is Chang Song-taek - the husband of Kim Jong-il's sister and director of the administrative department of the North Korean Workers Party.
Some analysts see him acting as a "regent" to Kim Jong-un until he is ready to rule on his own.
'Morning Star King'
Kim Jong-un's mother, Ko Yong-hui, was thought to be Kim Jong-il's favourite wife, and she clearly doted on her son, reportedly calling him the "Morning Star King".
In his 2003 book, "I was Kim Jong-il's chef", a Japanese man writing under the pseudonym Kenji Fujimoto also claimed that Jong-un was his father's favourite.
Kim Jong-il reportedly suffered a stroke last year
But the mysterious death of Ko Yong-hui in 2004 appeared to put the younger Kim firmly behind his half-brother Jong-nam in the leadership stakes.
However Jong-nam's deportation from Japan in May 2001, and middle brother Jong-chol's apparent "unmanliness" subsequently improved his chances.
Swiss-educated like his brothers, Kim Jong-un avoided Western influences, returning home when not in school and dining out with the North Korean ambassador.
Since his return to Pyongyang, little has been made public about his character.
In 2006, badges bearing his image were said to be circulating among senior officials of the ruling Korean Workers' Party, arousing suspicions that he had been chosen as Kim Jong-il's successor.
In his father's image
Said by Kim Jong-il's chef, Mr Fujimoto, to be the "spitting image" of his father, the young Kim has never been photographed by the Western media.
The only photograph known to exist of him is one taken when he was 11 which Mr Fujimoto said he was given by Kim Jong-un before he left North Korea.
Kim Jong-un also shares some of his father's health problems, and is reported to already have diabetes and heart disease due to a lack of exercise.
Like his film-loving father, Jong-un is said to enjoy popular culture, and is apparently a fan of NBA basketball.
One South Korean newspaper, the Dong-a Ilbo, has reported that the North was teaching its people a song lauding Kim Jong-un to raise his profile and in January 2010, North Korean defectors reported that his birthday had been designated a national holiday.
But these details, as with many others in secretive North Korea, are impossible to confirm.