Today marks the 31st anniversary of the Gwangju Massacre (also commonly referred to as the Gwangju Democratization Movement, 광주민주화운동, Gwanju Uprising, 광주민중항쟁 or 518). On May 18, 1980 several thousands of protesters gathered in the city of Gwangju to protest the dictatorial rule of president Chun Doo Hwan. The uprising was violently supressed by the army but paved the way for democratization and was the beginning of a national struggle for freedom and democracy. More than 150 people were killed and over a thousand arrested during the protests.

KBS: S.Korea Marks May 18 Pro-democracy Movement

Wall Street Journal: Koreans Remember 1980 Uprising

Yonhap: Lee calls for efforts toward advanced democracy

Hankyoreh: Across the country, celebrations for May 18

Wikipedia: Gwangju Democratization Movement

위키백과: 5·18 광주 민주화 운동