CNN  — 

Tributes are flooding in for photographer Li Zhensheng, who documented the violent and tumultuous years of China’s Cultural Revolution in the ’60s and ‘70s.

A spokesperson for The Chinese University of Hong Kong Press, which published a book containing sensitive images Li once kept hidden under his floorboards, this week confirmed his death at the age 79 and described his work as “incomparable.” Li’s photos represented “the most comprehensive and systematic visual archive” of Communist leader Mao Zedong’s devastating campaign, the statement said, praising the photographer’s ability to “generate a feeling of empathy about the disaster.”

Li’s agency, Contact Press Images, announced his death with an Instagram post saying that he leaves behind “an inestimable photographic legacy,” while the UK’s Photographers’ Gallery, one of the dozens of institutions to share his shocking pictures with the world, tweeted that his “important work had a lasting impact on everyone who saw it.”

Li came to international prominence in the 1990s, when he began publishing harrowing photos from the Cultural Revolution in Western media outlets. Through a combination of reportage and street photography, he shone a new light on the decade-long political campaign responsible for the deaths of hundreds of thousands of people and the persecution of tens of millions more.

A provincial governor in Heilongjiang has his hair brutally shaved and is forced to bow for hours after being accused of bearing a resemblance to Mao Zedong.

As an accredited photographer for the Heilongjiang Daily newspaper, Li was tasked with documenting the revolutionary fervor that swept the nation from May 1966. As such, many of his images showed – enthusiastic Chinese youth and Red Guards – painting posters, waving banners and sporting political armbands and copies of Mao’s “Little Red Book.”

But he also captured examples of shocking violence committed against those denounced as public enemies or counterrevolutionaries, including scenes of public humiliation and torture (so-called “struggle sessions”), and even roadside executions. For years, he hid thousands of the negatives, before sharing them with the world in the decades following Mao’s death in 1976.

According to his friend Liu Heung Shing, a Pulitzer Prize-winning photographer and founder of the Shanghai Center of Photography, Li’s work not only shows him to be an accomplished photojournalist, it offers a visual record of a heavily-censored period of history.

“One thing that was very stark from Li Zhensheng’s archive is all those executions and the purging of senior officials,” Liu said in a phone interview. “The value of this work is self-evident, because there’s not a body of work that properly documents the madness that Mao unleashed.”

Swimmers read from Mao's "Little Red Book" as they prepare to commemorate the second anniversary of the leader's famous swim in the Yangtze.

Liu also sought to rebuke suggestions that his late friend somehow enabled or supported the Cultural Revolution by working in an official capacity during those years.

“If you were there without an official press card you would have been lynched by the mob,” he said.

‘Red-colored news soldier’

Li was born in 1940 in Dalian in northeastern China’s Liaoning province, which was then under Japanese rule. He studied cinematography before joining Heilongjiang Daily as a photographer in 1963.

Like many young men at the time, he was sent to undergo “reeducation” in the countryside, returning to Heilongjiang province’s capital, Harbin, just months before the Cultural Revolution was launched in 1966.

Li’s position at a state-run newspaper gave him the freedom to capture the subsequent turmoil in rare detail, though a “lack of film, marauding Red Guards and a political dictate against photographing ‘negative’ scenes, all conspired to reduce him to the level of a propaganda functionary,” wrote American writer and filmmaker Jacques Menasche in an official biography.

 A 2008 self-portrait taken by Li Zhensheng.

He was later denounced and forced to undergo hard labor with his wife for two years. Yet, rather than destroying images that painted the period in a bad light, Li kept them stashed away in his apartment.

Among the most shocking was a photograph of seven men and a woman lined up on their knees in front of a firing squad, moments before their execution in 1968. Another showed a provincial governor, Li Fanwu, having his hair shaved in public as he was made to bow for hours underneath a portrait of Mao.

In the late 1980s, when China underwent a period of liberalization, he publicly exhibited a number of images in Beijing (to the shock of state-controlled newspapers) as open criticism of Mao became gradually more acceptable. With Liu’s help, Li, who was then still living in Harbin, collaborated with Time magazine on a 1996 feature marking the 30th anniversary of the start of the Cultural Revolution.

Li’s work would later appear in a number of Western media outlets. And in the late 1990s, he sent some 30,000 archival pictures of the Cultural Revolution to the international photo agency, Contact Press Images, in brown paper envelopes. The resulting book “Red-Color News Soldier” (a translation of the phrase printed on his official press armband) was published in 2003 and was translated into multiple languages.

A Chinese-language edition was eventually published in Hong Kong in 2018, though it was banned from sale in mainland China. And while Li continued to give talks at Chinese universities, and split his time between New York City and Beijing, his images were still considered taboo in his home country.

“We’ll bring the books into the mainland one by one,” he told the New York Times last year after the Chinese edition’s release. “It’ll be like ants moving house.”

Li’s friend Liu (who is himself known for documenting a sensitive period in Chinese history – the Tiananmen Square protests of 1989), said the late photographer resented the lack of recognition of his work in China. In interviews, Li often expressed frustration that his photos were effectively banned in the one place where they could have most impact.

“The Cultural Revolution took place in China, but research into the Cultural Revolution flourishes in other countries and it has little impact on China. I really cannot accept this,” Li told the South China Morning Post in 2018. “My photos were taken in China and most of my readers should be in mainland China, whether or not they have experienced the Cultural Revolution.”

According to his Hong Kong publisher, Li asked his family to pass a message onto his friends upon his death: “I have dedicated my whole life to witnessing and recording history, and now I rest in history.”