June 4 marks the anniversary of the Tiananmen Square massacre, when, the China’s People's Liberation Army, under orders from the government, brutally killed protesters, most of them university students. This was followed by media gags, expulsion of foreign journalists, and destruction of evidence.

One iconic image from the bloody episode that emerged though was of a young man standing against the state’s military might. On June 5, 1989, tank man as he has come to be called, firmly planted himself in front of approaching cavalcade, refusing to let them pass.

The pro-democracy protest had started following the death of noted reformer and Communist Party General Secretary Hu Yaobang on April 15, 1989. The demonstration at Tiananmen Square was meant originally to grieve Yaobang’s death, but over the next ten days took on a decidedly political character. Protesters demanded political freedoms like free speech, a free press, and an end to official corruption.

The government imposed martial law on May 20, as the protests grew and spread. On June 3 the army marched on to the square. An official US intelligence report from the time reads: “Deaths from the military assault on Tiananmen Square range from 180 to 500; thousands more have been injured.” It adds how “thousands of civilians stood their ground or swarmed around military vehicles. APCs (Armoured Personnel carriers) were set on fire, and demonstrators besieged troops with rocks, bottles, and Molotov cocktails.”

The Chinese Communist Party has tried to erase the massacre from public memory. A piece in Quartz points at how references to the massacre are censored online, and the terms internet users have come up with to refer to the event.

As to the fate of tank man, it's not clear. His real identity remains unknown, and while some believe he was whisked away by concerned onlookers, others think he was arrested, while yet others believe he is still alive.

Another theory suggests he was mentally unstable. A photo of him taken from another perspective wasn't published until 2009. It shows him standing calmly prepared for the tanks, as others around run for cover.