When Kim Jong Un emerged as the heir apparent of North Korea a decade ago, the world knew so little about him that the South Korean intelligence service even spelled his name wrong. When it came to his age, they could hazard only a rough guess.

The world has come to know a bit more about him over the intervening years. He’s shown himself to be every bit as ruthless as his father and grandfather before him, and remarkably adept at running the world’s last bastion of Stalinism. And he’s earned himself the dubious distinction of being the youngest leader of a nuclear-armed state. But there are still many more questions than answers. Chief among them: How did an overweight 27-year-old with no qualifications rise to the top of a regime stacked with octogenarian generals and a country where malnourishment remains rife? And how, once there, did he manage to keep his job for one and then two and now more than eight years?