Kim Jong Il, supreme leader of North Korea, died on Saturday at the age of 69 after suffering a fatal heart attack. The Great Successor of North Korea's Dear Leader will be his son, Kim Jong Un.

But who exactly is Kim Jong Un? The youngest son of Kim Jong Il's three sons, aged 27 or 28, Kim Jong Un will be one of the most elusive individuals to rise to power. Little information is known about this young man who will come into significant power in a country he can reform, maintain or let slip into chaos, according to The Washington Post.

North Korea has held just two leaders in the past 63 years, Kim Jong Il and Kim Il Sung. Kim Jong Un, the third to rise to the title of Dear Leader, is now in control of the impoverished country and its nuclear arms. 

Under the leadership of Kim Jong Eun, North Korea's state-run media stated, we should turn our sorrow into strength. North Korea attested in the statement that both its military and its citizens have pledged to uphold the leadership of comrade Kim Jong Un.

So what is known about Kim Jong Un? 

Kim Jong Un reportedly attended school in Bern, a suburb in Switzerland, under a pseudonym. Indeed, its presence is wrapped in an incredible mystery, said Julie Zaugg, a journalist with the Swiss magazine L'Hebdo. At the International School of Gümlingen, located a few meters from the North Korean Embassy, ??the adolescent was written under the pseudonym 'Pak Chol' and posed as the son of a chauffeur. An older student that he called 'Chol Wang,' accompanied him at all times. This provoked suspicion amongst his classmates.

Student at Bern's German-speaking Liebefeld-Steinholzli School described him as unremarkable and obsessed with basketball.

He proudly showed off photographs of himself standing with Toni Kukoc of the Chicago Bulls and Kobe Bryant of the Los Angeles Lakers. It is unclear where the pictures were taken. On at least one occasion, a car from the North Korean Embassy drove Pak Un to Paris to watch an NBA exhibition game, the source said.

Kim Jong Un supposedly never spoke of anti-American sentiment and seemed indifferent to political issues. He was shy with girls but a formidable competitor on the basketball court.

A fiercely competitive player, said classmate Nikola Kovacevic. He was very explosive. He could make things happen. He was the playmaker. 

He also had a collection of Nike sneakers.  We only dreamed about having such shoes. He was wearing them, recalled Kovacevic, who thinks each pair cost about $200. 

Supposedly he was groomed as a youngster by the former ambassador to North Korea in Switzerland, Ri Tcheul. He had come for Kim in a Limousine to Berne and rumors say it is split by a deep reverence on seeing him, said Ron Hochuli, a journalist for the Swiss Television. To me, he did not leave Switzerland by chance perhaps to support Kim Jong-un in his rise to power. Ri Tcheul was a real babysitter for all the siblings!

Kim disappeared in 2000, when he should have entered into middle school. Apparently, at this time, he returned to Pyongyang, reports The Washington Post. Kim Jong Un had not been seen in public until he emerged as his father's heir-apparent last year.

Experts say that Kim Jong Un does not have the experience to rule the country in the rigid manner of his father and grandfather, according to The Washington Post. However, security experts have stated that the Great Successor is likely to turn North Korea into a volatile state, one more likely to provoke its neighbors and show civil conflict.

Others have also expressed concern over the shift in power. With the power center, Kim Jong Il, now gone, there are fewer common interests to hold top officials together, said Ryoo Kihl-jae, from the Seoul-based University of North Korean Studies.

Some have gone one step further, anxious about the potential for unrest within the legion of state officials who deem Kim Jong Un too young to rise to power.

This is really the worst possible nightmare for the North Korean state - this sudden death, and for the son to be taking over, said Victor Cha, the White House's former director of Asian affairs. This could collapse before our eyes.