In innocent black-and-white family photographs from decades ago, toddler Kim Jong-il stands side by side with Kyong-hui, his angel-faced younger sister, writes Christian Oliver in Seoul.

Kyong-hui is still widely seen as the only person Mr Kim, the North Korean dictator, has always been able to trust. Their bond became more public on Tuesday when she was named a four-star general along with the dictator’s son, Kim Jong-eun.

Mrs Kim, 64, is being groomed to play an important role in keeping the state alive, especially in the event that her brother dies suddenly. She has been a prominent companion on her brother’s recent trips around the country to factories, farms and operas, a signal to North Korean elites that she is someone to whom Kim Jong-il has confided his plans.