DEREK JARMAN, the radical film-maker who treated cinema as if it were a painter’s blank canvas, died ten years ago today and is being celebrated this weekend with retrospectives at the ICA and Tate Britain. Jarman was the fiercely independent champion of low-budget film-making who straddled the classical and the pop. Always experimental and always provocative, he was as comfortable making music videos for the Pet Shop Boys as he was adapting Shakespeare and Marlowe, or savaging 1980s Britain in his apocalyptic cine-poem The Last of England.

One particular event in the summer of 1993, seven months before his death, says a lot about Jarman. He managed to hush a noisy crowd of music fans when he appeared unexpectedly before the start of an Aids benefit gig in a small London theatre. Addressing the crowd from a box, his frail hands clutching a microphone, Jarman — at the time seriously ill with Aids — passionately advocated the campaign to lower the age of homosexual consent from 21.

He was a committed political activist, especially in the last years of his life. He was diagnosed HIV positive in December 1986 and spent the next seven years working as hard as his body allowed, and embracing his condition directly in his work (most powerfully in his final film Blue in 1993 which consisted only of a blue screen and a voiceover).

Between his diagnosis and his death, Jarman made six feature films, wrote three books, was the subject of several art exhibitions and returned to his passion of gardening at his seafront fisherman’s cottage in Dungeness, Kent.

“My body was thrown into the struggle, bringing me into a spotlight in a way I never expected or wanted,” Jarman wrote in 1991. “On December 22, 1986, finding I was body positive, I set myself a target: I would disclose my secret and survive Margaret Thatcher. I did. Now I have my sights on the millennium and a world where we are all equal before the law.”

Jarman’s entry into film-making in the early 1970s was initially a playful offshoot to his career as an artist. After studying at the Slade in the mid-Sixties he worked as a successful painter and theatre designer. His first work in film came when he created the set design for Ken Russell’s The Devils in 1970 and began to experiment with a friend’s Super 8 camera.

From the start, the daring aesthetics of Jarman’s feature films were revolutionary. Starting with Sebastiane in 1975, then the punk-inspired Jubilee (1977), The Tempest (1979) and The Angelic Conversation (1985) — all made before the wider success of Caravaggio (1986) — Jarman mixed film formats, embraced iconoclastic set and costume design, adopted a distinctive, painterly sense of composition and harnessed an anarchic spirit. Often, a single still from a Jarman film would not look out of place in an art gallery.

But it was Jarman’s unashamed and loud embrace of gay sexuality that made him a true radical. Peter Tatchell, the campaigner for gay rights, has said of Sebastiane, a retelling of the Catholic legend of St Sebastiane, replete with unrestrained homoeroticism, that it was “a real milestone, a watershed in both British cinematic history and in cultural representations of gay sexuality”.

If Jarman’s subjects sound traditional, then his approach certainly never was. In Edward II, for example, a contemporary gay rights protest bursts into the medieval royal court.

It was not until Caravaggio and the news of his illness that Jarman attracted wider attention. He loathed the perception of himself as “art house” or “avant-garde”. But even his more narrative-based films, such as Edward II and Wittgenstein, were as distant from the mainstream as you could get.

Since his death, many of Jarman’s collaborators and admirers have found it hard to reconcile the originality of his work with modern British cinema. In the summer of 2002, Tilda Swinton — Jarman’s favourite actress, with whom he worked on every film from Caravaggio to Blue — addressed an audience at the Edinburgh Film Festival on the state of British film. She delivered her speech as an open letter to Jarman.

“Dear Derek, Jubilee is out on DVD,” Swinton began. “It’s as cheeky a bit of inspired old ham punk spunk nonsense as ever grew out of your brain, and that’s saying something: what a buzz it gives me to look at it now. And what a joke: there’s nothing an eighth as mad, bad and downright spiritualised being made down here these days this side of Beat Takashi (Japan’s own edgy Renaissance man, a prolific actor and director).”

Swinton remembers first encountering Jarman in the mid-1980s. “I had run away to join a different circus myself — Planet Jarmania. He was the first person I met who could gossip about St Thomas Aquinas and hold a steady camera at the same time, as he did at our first meeting.”

Towards the beginning of Wittgenstein, the Austrian philosopher declares: “If people did not sometimes do stupid things, nothing intelligent would get done.” Jarman’s career, too, was marked by bold experiment. He moved effortlessly between incarnations — film-maker, artist, writer, political activist and gardener — with a willingness to explore uncharted territory without fear of failure or ridicule.

• This Sunday the ICA (020-7930 3647) will screen Caravaggio and Derek Jarman: Life as Art; Tate Britain (020-7887 8888) will also be screening The Angelic Conversation

Explore Film

• Film Reviews

• Trailers

• DVD

• London Film Festival

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010