The humble item has been emblem of Hong Kong’s pro-democracy since 2014, first as a means of expression and then as a shield against police cameras, pepper spray, gas canisters and rubber bullets. But even the sturdiest umbrella cannot protect the protagonists of Kiwi Chow’s shocking documentary “Revolution of Our Times”, which chronicles the massive street protests that gripped Hong Kong in 2019 and their brutal suppression by police.

The secretive, last-minute inclusion of Chow’s film – announced only as a “surprise documentary” in an email to the press on Thursday – had aroused plenty of curiosity, as well as speculation that Cannes might be heading for a showdown with China’s criticism-averse authorities. As it turns out, fears of a fallout with Beijing are entirely justified: “Revolution of Our Times” is a powerful tribute to the courage and resilience of Hongkongers battling for their freedom, and an uncompromising critique of Chinese threats to the city’s semi-autonomous status.

“We’re not playing a game with this surprise screening,” festival director Thierry Frémaux told the audience ahead of the film’s premiere, perhaps hoping to defuse a potential diplomatic spat. Frémaux said the documentary had reached Cannes at the 11th hour, adding: “We saw it, we loved it, and in accordance with Cannes’ long tradition of showing films about what’s happening in the world, we decided it was important to screen it.”

Chow has amassed extensive footage of the marches and the protesters’ pitched battles with police, much of it chillingly graphic. His film also features a wealth of interviews with ordinary citizens involved in the movement, their voices altered and their faces hidden by masks or blurred in post-production. The film states that it was “made by Hongkongers” and that most people involved use pseudonyms in the credits. Endnotes stress that several people in the film are now in exile or in jail.

“Over the past fifty years, Hongkongers have fought for freedom and democracy but have yet to succeed,” reads the film’s synopsis, published on the festival’s website. “In 2019, the Extradition Bill to China opened Pandora’s box, turning Hong Kong into a battlefield against the Chinese authoritarian rule.”

That Hongkongers broadly support the protests is immediately obvious from images of a monster demonstration bringing two million people – almost a third of the total population – to the city’s streets. But the film’s focus is really on the so-called “Valiant”, the overwhelmingly youthful, black-clad protesters who believe that attacking is the best defence. “Be water” is their motto, constantly changing shape and flow, and the film is perhaps most absorbing in its portrayal of their fluctuating tactics (some inspired by video games).

A visceral experience, “Revolution of Our Times” brings to the fore the texture of protest: the energizing kick of revolutionary action, the bonds of comradeship, the pain from pepper spray and rubber bullets, the agony of parents who cannot reach their children, and the anguish of girls whose menstrual blood runs black from inhaling too much tear gas. It also documents the dismay of Hongkongers at the rapid escalation of violence in a city unaccustomed to this level of brutality

“Do you even realize your police force is out of control?” a human rights activist asks stoned-faced officials at a police briefing as bloodcurdling footage of an officer shooting an 18-year-old in the chest at point-blank range goes viral. While youths drive the protests, older generations look on aghast as their cherished city-state is altered beyond recognition. “In such a civilized place, how can the governance be so barbaric?” asks one veteran campaigner, appalled by the police’s growing violence.

Chow makes little attempt to give the police’s perspective; his film is very clear as to which side we should all be rooting for. It is both a tribute to the bravery and extraordinary resilience of youths in the face of brutal repression, and a plea for help. As one activist puts it, “Hong Kong is the frontier of the free world against totalitarian systems.”

The director expressed his gratitude to the Cannes Film Festival for screening his documentary. In an emailed statement, Chow wrote: “It is our honor to have the World Premiere of ‘Revolution of Our Times’, a film documenting the struggle of Hongkongers, at Cannes; and receive great attention. Hong Kong has been losing far more than anyone has expected, this good news will be a comfort to many Hongkongers who live in fear; it also shows that whoever fights for justice and freedom around the world, ARE with us! And Hongkongers are staying strong!”

Chow’s film will not receive official screenings in Hong Kong. Under a controversial National Security Law imposed by Beijing in 2020, the director and others involved in the film could even face arrest and prosecution.