On May 4, 1989 a peaceful protest marched on Tienanmen Square demanding democratic reform. There they gave speeches on freedom and love of country, reaching numbers in excess of 300,000. On May 20th martial law was declared and the protesters ordered to disperse, and a fair number of them refused.
On June 3, elements of the 27th and 28th Armies of the PLA began the crackdown, killing 1000-7000 and wounding tens of thousands with small arms and tank treads. The bust would culminate with a bayonet and bullet sweep of the Square itself ending early in the morning of June 4.
The CCP had the event expunged from their history books, and we here in the free world have in large part expunged it from our collective memory.