Seoul (AFP) - Six years after inheriting power from his father, Kim Jong Un has established his authority domestically, taken North Korea to unprecedented nuclear heights, and is now looking to flex his muscles abroad.
Kim's shock visit to Beijing -- traditionally Pyongyang's strongest backer, although the relationship has soured during his time in power -- is the first time he is known to have set foot outside the impoverished North since he assumed the leadership.
But Kim, who is in his mid-thirties, has repeatedly shown an ability to stamp an outsized footprint on the global stage without ever leaving home.
The third member of the Kim dynasty to rule the North, he has turned his country into a bona fide nuclear power with intercontinental ballistic missiles he says can reach across the globe, including the United States -- with state media regularly picturing him overseeing launches.
And he secured a major diplomatic breakthrough for his ostracised regime earlier this month when US President Donald Trump said he would be willing to hold summit talks with the young leader.
It is a marked contrast to the situation when he took over in his 20s, when he was considered untested, vulnerable and likely to be manipulated by senior figures in an opaque and ruthless country.
But he has proved his mettle in dealing harshly -- sometimes brutally -- with any sign of dissent, even at the highest levels, while maintaining an aggressively provocative stance with the international community.
- Rivals purged -
At home Kim has amassed absolute control over both the party and the military, at times ruthlessly purging potential rivals.
The most senior victim was his uncle and mentor Jang Song Thaek, who was suddenly executed in 2013, denounced by state media as "despicable human scum" and proclaimed guilty of a variety of colourful crimes and political sins.
Then there was the brazen daylight assassination last year of his half-brother Kim Jong Nam, sprayed with a deadly nerve agent as he walked through Kuala Lumpur's international airport, in a hit most analysts say could only have come from Pyongyang.
Rights groups say abuses are rampant in the North, where between 80,000 and 120,000 prisoners languish in political prison camps.
But Kim has also been keen to project a softer side, at least in official propaganda.
Unlike his father, who rarely smiled or spoke in public, the carefully vetted images of Kim Jong Un's heavily choreographed appearances show a more garrulous figure, laughing and joking with officers, soldiers and civilians during field trips, as well as giving speeches to packed halls of party functionaries.
He has noticeably modelled his image on that of his grandfather Kim Il Sung, appearing to mimic his hairstyle, dress, mannerisms and public speaking style.
- Lap of luxury -
But unlike the North's founder, whose youth was dominated by the anti-Japanese struggle, Kim Jong Un has led a life of luxury.
He was born to his father's third wife, Japan-born ethnic Korean dancer Ko Yong Hui, who is believed to have died of breast cancer in 2004.
Much of his early history is still surrounded in mystery -- so much so that even his precise date of birth is unclear.
Kim was sent to school in Switzerland, where he was looked after by his maternal aunt Ko Yong Suk and her husband.
School staff and friends, who were reportedly unaware that he was a member of North Korea's ruling family, remembered him as a shy boy who liked skiing, Hollywood tough guy Jean-Claude Van Damme and basketball.
He is said to have known that he would become North Korea's leader from his eighth birthday, when he received a general's uniform and the country's military top brass bowed to him.
But Kim only entered the public eye in 2008 when his father suffered a stroke and Pyongyang revved up plans for the nation's second dynastic succession.
Pyongyang is extremely sensitive and protective when it comes to the image of the ruling family, and Kim's father and grandfather are ubiquitous, their portraits adorning every home and office in the country while their bodies lie in state at the capital's Kumsusan Palace.
Despite his overseas education, Kim Jong Un is not known to have made any previous foreign trips since coming to power, and the most prominent American he has met is his basketball idol Dennis Rodman, who has made multiple visits to Pyongyang.
That makes Kim's journey to Beijing a diplomatic "coming out" ahead of planned summits with Trump and South Korea's President Moon Jae-in.