He served as the Chairman of the Supreme People's Assembly from 1972 to 1983 and was largely responsible for crafting Juche, the state ideology of North Korea.

He also supervised the rewriting of Korean Communist history to make it look like Kim had been the founder and leader of the ruling Workers' Party of Korea from its inception.

[7][8] Once their true identities were discovered, Pyongyang immediately threatened retaliation, while Beijing police sealed off the South Korean embassy.

[5] After his arrival in South Korea, he became a harsh critic of North Korea, publishing over 12 books and treatises, many of which accused Kim Jong Il of "betraying Juche and building feudalism instead of socialism", and used his position as chairman of the Unification Policy Research Institute to spread his message.

However, under the Sunshine Policy of president Kim Dae-jung, who took office in 1998, Hwang found himself increasingly marginalised; in November 2000, he was removed from the chairmanship of the Unification Policy Research Institute, leading him to complain that the South Korean government wanted him to stay quiet so as not to upset the North.

They claimed that they would receive assistance from North Korean sympathisers in the South, but refused to give any names when questioned.

[1] He died while bathing, and as such a large amount of water entered his lungs; however, an autopsy found no poison or drugs in his body, and footage from surveillance cameras showed no signs of forcible entry.

On those grounds, the Seoul Metropolitan Police Agency (SMPA) stated that there was no evidence that his death might be murder and that they would close their investigation.