On December 10, 1979 (International Human Rights Day), members of Taiwan's Dangwai ("Outside the Kuomintang") movement and staff of "Formosa Magazine" gathered in Kaohsiung to organize mass demonstrations and speeches. They demanded democracy and freedom, and an end to martial law and bans on political parties. That day, supporters of the Kuomintang (National People's Party, KMT) confronted the protesters at the rally site. The police suppressed the demonstration with tear gas and riot-suppression vehicles. This incident is now regarded as the most serious conflict between police and the public in post-February 28 Incident Taiwan. After the Formosa Incident, the Taiwan Garrison Command (a quasi-military secret police force) arrested Dangwai people on a massive scale. Beginning March 18, 1980, nine courts-martial were held. More than 150 people were involved in the trials, including Huang Hsin-chieh, Shih Ming-te, Lin Hung-hsüan, Lin I-hsiung, Yao Chia-wen, Annette Lu Hsiu-lien, Chang Chun-hung and Chen Chu.

The leader of the movement, Shih Ming-te, was originally sentenced to death for treason. Under pressure from many sectors of society, including US congress-members, the sentence was finally commuted to life imprisonment. Huang Hsin-chieh was sentenced to 14 years in prison, and the other six were sentenced to 12 years in prison each. For the first time, the government allowed newspapers to publish the trial process and the defendants' statements. At that time, the KMT government was facing diplomatic setbacks, including the Republic of China's withdrawal from the United Nations and the establishment of formal diplomatic relations between the People's Republic of China and the US. Coupled with challenges from domestic and Dangwai forces, the legitimacy of KMT one-party dictatorship was questioned. Finally, in 1987, facing pressure both domestic and international, the KMT government finally announced the lifting of martial law. The Formosa Incident continues to be regarded as an important milestone in the course of Taiwan's democratization.

References: [BBC中文網("BBC News Chinese Edition")(Chinese)] (https://www.bbc.com/zhongwen/trad/world-50726110); Executive Yuan Research, Development and Evaluation Commission (https://www.archives.gov.tw/UserFiles/美麗島事件檔案展導引(1).pdf)