"Ideologically sick and extremely idle and easy-going, he used drugs and squandered foreign currency at casinos while he was receiving medical treatment in a foreign country under the care of the party."
Jang was long seen as the power behind the throne and a key policy adviser to the Supreme Leader. He was also regarded as Kim's mentor.
He solidified his position by dismantling the power structure put in place by Kim Jong-il before his death in 2011, according to reports.
In July 2012, the general removed two military officials who were appointed by the late North Korean leader. U Dong-chuk, first deputy director of the State Security Department, and army chief Ri Yong-ho were sacked by Jang seven months after Kim Jong-un became Supreme Leader.