Now, astonishingly, state media say someone tried to usurp the leadership. And not just anybody, but a man closest to the leader because of family ties and shared history. Jang was once also seen as the closest thing the country had to a reformer and a darling of Beijing, which is North Korea's only major ally.
"We now know for sure that the Kim regime is afraid of the emergence of a renegade insider who may attempt to take advantage of the North's economic problems and the people's yearning for a better life to seize power with military backing," Alexandre Mansourov, a North Korea specialist, wrote on the website 38 North. "This prospect keeps Kim Jong Un awake at night."
The portrayal of the Jang episode in North Korea's propagandist media, which had always tried to cloak Kim Jong Un in greatness, also opens up the leader to suggestions that he was a bad judge of character.
"What is remarkable here is that Kim clearly trusted Jang," Adam Cathcart, a history lecturer at the University of Leeds and editor of SinoNK.com, wrote in a recent analysis of the state media reporting about Jang's fall. "Why would Kim be so naive as to install a man so dangerous in his inner circle? It's a question that's implicit in the article - but one that must not be asked."
There will be little public questioning in Pyongyang of what's actually happening, of course.
State media are already getting back to business as usual. Kim Jong Il is being glorified in the run-up to his death anniversary. Kim Jong Un has visited a military institute, a ski resort, a fish factory, all in keeping with the long-standing propaganda message that he's deeply engaged in the business of running the country.
Jang's wife, who is Kim Jong Il's sister, has also been listed prominently in state media, an indication that she has survived her husband's purge, at least for the time being. South Korea, meanwhile, sees no signs of unusual North Korean military activity, though Seoul is boosting border security just in case.
The recent purge may show that Jang and his cronies represented a genuine threat to Kim's leadership, according to Charles Armstrong, a history professor and Korea expert at Columbia University. Or it could show "a ferociously vindictive, ruthless and egotistical" Kim Jong Un wanted "to send an unmistakable message that he was the man in charge."
"But exposing an absurd list of crimes, some of which may sound quite plausible to the average North Korean, is very risky as it overturns the official narrative of unified leadership and smooth succession that the regime has articulated during the last two years," Armstrong wrote in an email.
At the very least, it suggests a serious misstep by Kim Jong Un and his propaganda specialists.
"The Kim dynasty legend is the main capital he has, and he's squandering it like there's no tomorrow," said B.R. Myers, a North Korea scholar and professor at South Korea's Dongseo University.
