On January 8, 1976, Zhou Enlai died at the age of 78. In the three months that followed, in spite of opposition from the central government, the masses held mourning activities in various places and expressed their resistance to the Cultural Revolution (pro-Maoist) faction. From April 4 to April 5, crowds gravitated toward Beijing's Tian'anmen Square to protest against the Gang of Four; this span of time came to be known as the April 5 Tian'anmen Incident. It was the first large-scale peaceful protest the Chinese Communist Party (CCP) had faced since the founding of the People's Republic of China.

Zhou Enlai had been an important assistant to Mao Zedong in carrying out the Cultural Revolution; however, after Lin Biao broke ties with Mao Zedong and died in a plane crash, Mao and Zhou disagreed in their criticisms of Lin Biao. This split meant that Zhou Enlai was subjected to "rectification" during the Counterattack the Right-Deviationist Trend of Historical Revisionism movement and in the Criticize Lin, Criticize Confucius movement. Therefore, members of the public who felt opposition to the Cultural Revolution sided with Zhou Enlai, and expressed their appreciation for him after his death.

April 4 of 1976 was Qingming Festival (or "Tomb-Sweeping Day"), the traditional day of mourning the dead. On this day, millions of people gathered in Tian'anmen Square. In the early morning of April 5, the Beijing municipal government dispatched trucks to remove all the commemorative wreaths from the Square.

The next morning, people angrily shouted the slogan "Return our wreaths, return our comrade-in-arms"; they then clashed violently with the militia and police. At 2pm, the Politburo held an emergency meeting and decided to have Wu De, Secretary of the Beijing Municipal Party Committee, deliver a speech at 6:30pm. They also attempted to mobilize the masses to leave the Square, and organized the militia to surround the Square at 8:30pm. However, the crowd did not dissipate; it was not until 11 o'clock that the authorities began forcibly clearing the Square, dispersing the crowd with sticks, fists, and kicks.

After the April 5 Tian'anmen Square Incident, a CCP Central Committee Politburo meeting characterized it as an "flat-out counter-revolutionary incident"; some suggested that Deng Xiaoping had even been on site personally to coordinate the riots in the Square. On the evening of April 7, the Central People's Broadcasting Station broadcast two Central Committee resolutions: one would revoke all of Deng Xiaoping's positions inside and outside the Party; and the second would make Hua Guofeng the First Vice Chairman of the CCP Central Committee and State Council premier. After that, major cities across the country held celebrations, where they denounced Deng Xiaoping's crimes and celebrated Chairman Mao's great victory in clearing away the traitorous rebels.

Two years later, the April 5 Tian'anmen Incident was vindicated.

References: Yang Jisheng, "The World Turned Upside Down: A History of the Chinese Cultural Revolution"; Yin Hongbiao, "Footprints of the Missing: Trends of Thought of Young People During the Cultural Revolution"; Roderick MacFarquhar and Michael Schoenhals, "Mao's Last Revolution"