1989 Tiananmen Square protests and massacre
Protests led by students and workers, known in China as the June Fourth Incident, were held in Tiananmen Square in Beijing, China, from 15 April to 4 June 1989. After weeks of unsuccessful attempts between the demonstrators and the Chinese government to find a peaceful resolution, the Chinese government initiated martial law in late May and deployed troops to occupy the square on the night of 3 June in what is referred to as the Tiananmen Square massacre.
Source: Wikipedia — 1989 Tiananmen Square protests and massacre (CC BY-SA 4.0)