South Korea became a democracy only in the late 1980s, and military intervention in civilian affairs remains a touchy subject.

During the dictatorships that emerged as the country rebuilt from the destruction of the 1950-53 Korean war, leaders occasionally proclaimed martial law that allowed them to station combat soldiers, tanks and armoured vehicles on streets or in public places to prevent anti-government demonstrations.

Such scenes are unimaginable for many today.

The dictator Park Chung-hee, who ruled South Korea for nearly 20 years before he was assassinated by his spy chief in 1979, led several thousand troops into Seoul in the early hours of 16 May 1961, in the country’s first successful coup.

During his rule, he occasionally proclaimed martial law to crack down on protests and jail critics.

Less than two months after Park Chung-hee’s death, Maj Gen Chun Doo-hwan led tanks and troops into Seoul in December 1979 in the country’s second successful coup. The next year, he orchestrated a brutal military crackdown on a pro-democracy uprising in the southern city of Gwangju, killing at least 200 people.

In the summer of 1987, massive street protests forced Chun’s government to accept direct presidential elections. His army ally Roh Tae-woo, who had joined Chun’s 1979 coup, won the election held later in 1987 thanks largely to divided votes among liberal opposition candidates.

Only with Roh’s inauguration on 25 February 1988, after 40 years under various forms of military-authoritarian rule, and with the enacting of its fifth constitution in that time, did South Korea become the current, democratic Sixth Republic.