Chun Doo-hwan

Yoon attended college in the early 1980s, when South Korea's military dictator Chun Doo-hwan ruled the country using martial law.

Roh Tae-woo, South Korea’s first democratic president, was sentenced to 17 years in prison for his role in the 1979 coup that brought military dictator Chun Doo-hwan to power and led to a civilian massacre.

Violent clashes sometimes took place, most indelibly in 1980, when then President Chun Doo-hwan extended martial law to deal with student protesters calling for democracy in the southern city of Gwangju.

A group of military leaders, led by General Chun Doo-hwan, declared martial law in 1980, banning political activities and arresting dissidents.

Yet, during his election campaign Yoon praised authoritarian general Chun Doo-hwan and said he had managed government affairs well – except for his suppression of pro-democracy activists.