HE has already demonstrated his ruthlessness by executing both his uncle and his one-time mistress, not to mention numerous other North Koreans who have incurred his displeasure.
But could Kim Jong Un, the country's new dictator, have purged even his own wife from his inner circle?
Speculation as to the fate of Ri Sol-ju, the petite former singer whom he married in 2009, is growing in the aftermath of the sudden death of Kim's uncle, Jang Sung Taek, whose execution for treason was announced by Pyongyang last Thursday.
The killing of a man until now regarded as a regime stalwart has demonstrated that even family members are not safe – and prompted anxious speculation about the fate of Ms Ri, who regularly appears by her husband's side, but has not been seen in public since October.
As a recent edition of the Daily North Korean, a Pyongyang-watching newspaper based in neighbouring South Korea, put it earlier this month: "Why Has Ri Been Gone for 48 Days?"
On Tuesday, video footage was released by North Korean media appearing to show the pair at a memorial service commemorating the second anniversary of the death of father, Kim Jong Il, from whom Kim took over as leader of the world's only hereditary communist republic.
But many North Korea experts claim the pictures were from a previous memorial service last summer, raising questions as to why there has so far been no live footage.
"Comrade Ri Sol Ju", who is understood to be in her late 20s, first caught Kim's eye as a singer in the Unhasu Orchestra, one of several musical glamour troupes that serve as in house-bands – and sometimes concubines – to the regime.
Little more is known about her – even her name is thought to be a pseudonym – although she is believed to harbour a ruthless streak herself.
Some reports say it was she who requested the recent execution of Kim's former mistress, Hyon Song-wol, who was also a performer in the Unhasu Orchestra.
Ms Hyon was machine-gunned to death along with eight other members of the Unhasu ensemble in August, allegedly because Ms Ri did not feel comfortable with the idea that Kim might see his one-time lover live on stage.
The following month, a Japanese newspaper, Asahi Shimbun, reported claims from a high-level North Korean defector that the Unhasu Orchestra members had been actually executed for making pornographic films. He further alleged that the execution was designed to cover up Ms Ri's own involvement in such films, and that this might presage her own fall from grace.
However, Ms Ri reappeared in public shortly after that, prompting more prosaic explanations that her absence from view since then may simply be to illness, or to the fact that she gave birth to Kim's daughter earlier this year. As with so much in the world's most secretive state, official photographs tell only part of the story.