3) Then it was off to Switzerland to attend boarding school.
Called "Pak Un" and described as the son of an employee of the North Korean embassy, Jong Un is thought to have attended an English-language international school in Gümligen near Bern.
4) Jong Un loved basketball and idolized Michael Jordan.
The young Korean reportedly had posters of Jordan all over his walls during his Swiss school days. Although Jong Un was overweight and only 5-6, he was a decent basketball player.
(Photo by Alexander Hassenstein/Bongarts/Getty Images)
5) After school in Switzerland, he returned home for military schooling.
Upon his return to North Korea, Jong Un attended Kim Il Sung Military University with his older brother. Some reports say they started to attend their father's military field inspections around 2007.
(Photo by Liu Xingzhe/ChinaFotoPress via Getty Images)
6) Jong Un has a theme song known as "Footsteps."
"Footsteps" looks and sounds like a propaganda song from the Soviet Union.
7) Many North Koreans see Jong Un as a youthful version of "Great Leader" Kim Il Sung.
Kim bears a clear resemblance to his grandfather, Kim Il Sung, in appearance, haircut, and mannerisms.
(Photo: Wikimedia Commons)
8) After his father died, Jong Un was quickly declared "Supreme Leader" of North Korea.
9. Some originally believed that Jong Un's aunt and uncle were actually calling the shots.
(Reuters TV / Reuters)
11. He's married to a former cheerleader and may have two kids.
(KCNA KCNA / Reuters)
10) But at the end of December 2013, Jong Un had his uncle and his uncle's family executed, apparently in a bid to stop a coup against his rule.
12) Jong Un lived out a childhood fantasy when former Chicago Bulls star Dennis Rodman visited.
Everyone in the family is apparently a huge Chicago Bulls fans.
(Photo courtesy of VICE)
13) But recently, things haven't been going so well.
In 2013 he was reportedly the target of an assassination attempt. South Korean intelligence believes the young leader was targeted by "disgruntled people inside the North" after he demoted a four-star general, which resulted in a power struggle.
(Photo courtesy: DPRK)
14. Jong Un has continued to be belligerent with South Korea and the West throughout his rule in hopes of bolstering his authority.
(KCNA KCNA / Reuters)
15. Jong Un's belligerence reached a peak in 2016.
This special unit was supposed to be ready by 2019, but plans have been accelerated. Han said he was worried about a "strategic or tactical provocation" in the coming months. The defense ministry says the unit will be ready "by this year."
Pyongyang has been acting up in recent months which has caused alarm. In December, North Korea broadcasted images in state media of Kim personally leading a combat drill against what "appeared to show a mockup of South Korea's presidential Blue House as a target."
Further, there have been reports North Korea potentially sees 2017 as the ideal time to advance its nuclear ambitions.
"Due to domestic political procedures, North Korea calculates that South Korea and the U.S. will not be able to take physical or military actions to deter North Korea's nuclear development,"
Thae added he thinks China will not be able to effectively lean on North Korea to halt its nuclear development because it prefers the status quo arrangement to a pro-U.S. unified Korea on China's border.
President-elect Donald Trump has complained that China should do more on the issue.
"China has been taking out massive amounts of money & wealth from the U.S. in totally one-sided trade, but won't help with North Korea. Nice!" Trump tweeted on Monday.