His feature-length film, “Pressure,” mapped the struggles of Black Britons in an era of unyielding racism. He was knighted in 2022.

Horace Ové, a prolific and groundbreaking Trinidad-born filmmaker and photographer whose 1975 film, “Pressure,” explored the fraught experience of Black Britons and is considered the first feature film by a Black British director, died on Sept. 16 in London. He was 86.

The cause was Alzheimer’s disease, said his son, Zak.

“Pressure” was made on a shoestring, shot in West London with neighborhood characters and Mr. Ové’s friends from film school volunteering their expertise. It was written with Samuel Selvon, a novelist from Trinidad, and it tells the story of Tony, a first-generation Briton and top student who has just graduated from school shouldering the expectations of his traditional West Indian parents and his own ambition, and navigating a community on the boil.

As he looks for a job to match his talents, he slowly realizes his is a fool’s errand in racist London. Tony’s older brother is a Black militant — born in the West Indies, he has no illusions about the limitations of the society he has landed in — and he exhorts Tony to join his activist struggle.

“Pressure” won awards and critical accolades when it was shown in film festivals in 1975, but it would take three more years to be widely released, as the British Film Institute, which had partly funded the movie, felt its depictions of police racism were incendiary. But Mr. Ové was documenting the climate of the times, and his own experience.

“The English ‘Deep South’ has always been the West Indies and Africa,” he told The San Francisco Examiner in 1971. “Until recently, they managed to keep it out of the country. The problem is more complicated in England than in America. In America it’s a visible thing. In England, it’s more of a mental violence.”

When “Pressure” was finally released in 1978, critics celebrated Mr. Ové as a significant Black filmmaker — “a talent with which we should reckon,” wrote The Sunday Telegraph — and roundly upbraided the British Film Institute.

“It seems palpably absurd to be welcoming Horace Ové’s ‘Pressure’ when the film, one of the most important and relevant the British Film Institute’s Production Board has ever made, was actually shot in 1974 and completed in 1975,” Derek Malcolm wrote in The Guardian. “The BFI should hang its head in corporate shame.”

In “Pressure,” Herbert Norville played the lead role of Tony, a recent graduate shouldering the expectations of his traditional West Indian parents and his own ambition.BFI National Archive & The Film Foundation

Mr. Ové had came of age as an artist in West London in the 1960s. It was a dynamic neighborhood, the heart of the British counterculture and also the Black Power Movement, of which Mr. Ové was an ardent participant.

He was a skilled photographer who captured the movement’s leaders and events, as well as his artist peers and Carnival, the ebullient multicultural Caribbean festival that had been exported to Notting Hill in the late 1960s by community activists as a way to celebrate their heritage and ease cultural tensions.

He met his second wife, Mary Irvine, at a socialist worker’s meeting; she was the fiercely political owner of a hip women’s clothing boutique called Dudu’s. (It sold no polyester or high-heeled shoes because she felt they were bad for women.)

They were a formidable duo. Their West Hampstead apartment became a hub for artists and radicals of all stripes. Michael X, the civil rights activist born Michael de Freitas in Trinidad, lived upstairs. Mealtimes began with the family raising their fists and declaring “Power to the people,” Zak Ové recalled.

James Baldwin was a family friend, and when he lectured at a West Indian student center with Dick Gregory, the comedian and activist, Mr. Ové made a compelling short documentary about it.

A 1967 photograph by Mr. Ové of Michael X, a civil rights activist, and the Black Power boys in Paddington Station.Horace Ové, via the Estate of Horace Ové

Mr. Ové was a documentarian at heart — his aesthetic was naturalistic — and he made a number of films for the BBC. “Reggae” (1971) was live footage and interviews that some critics described as that culture’s “Woodstock” movie. “King Carnival” (1973) was a critically acclaimed history of the Trinidad and Tobago Carnival. Skateboard Kings” (1978) chronicled the star skateboarders — the Dogtown crew — of Southern California.

“You can imagine Horace showing up in Venice Beach in a massive caftan swathed in African jewelry,” said Zak Ové. “Those kids looked at him and just fell in love.”

And then there’s “Black Safari” (1972). It’s a Pythonesque mockumentary about a group of African explorers searching “darkest Lancashire” for the heart of England along the Leeds and Liverpool canal, a good-humored spoof of the traditional colonial narratives.

Their boat is called the Queen of Spades, and Mr. Ové is its captain, a character named Horace Ové. Along the way, he and his crew mates have all sorts of adventures, like getting stuck in a lock, coming down with the flu and losing their tempers, witnessing the mysteries of clog dancing and suffering the noise of an oompah band.

Mr. Ové in 1979 on the set of “The Latch Key Children,” a television series he directed. via the Estate of Horace Ové

“For me, a director is a director no matter what color he is,” Mr. Ové told an interviewer in 2020. “Here in England there is a danger, if you are Black, that all you are allowed to make is films about Black people and their problems. White filmmakers, on the other hand, have a right to make films about whatever they like. People miss out by not asking us or allowing us to do this. We know you, we have to study you in order to survive.”

Horace Courtenay Jones was born on Dec. 3, 1936, in Belmont, a suburb in Port of Spain, Trinidad. His parents, Lawrence and Lorna (Rocke) Jones, ran a cafe and hardware store that sold basically everything, including goods for Carnival makers.

Horace changed his name to Horace Shango Ové when he emigrated to Britain in 1960. Like many who were involved in the Black Power movement, he wanted to shed his so-called slave name for one that reflected his African heritage. Shango is the Yoruba god of thunder, lightning and justice. But the meaning of “Ové” is still a mystery, Zak Ové said. “It’s a bit like Rosebud,” he said. “I never got a proper answer.”

Mr. Ové in the early 1940s in Belmont, Trinidad, with his grandmother, Imelda. The Estate of Horace Ove

Horace Ové was 24 when he left for England to pursue a career as an artist or an interior designer. He lived in Brixton and West Hampstead, communities populated by West Indian immigrants who had been lured to Britain in the post World War II years by the promise of good jobs, only to be met by offers of menial work and abject racism; Mr. Ové recalled the “No Blacks” signs in the windows of boardinghouses there.

He worked as a porter in a hotel, on a fishing boat in the North Sea and as a film extra. When he was cast as a slave in the 1963 film “Cleopatra,” starring Elizabeth Taylor and Richard Burton, the production moved to Rome. He stayed three years, working as a painter and a photographer, and he returned to London determined to make movies, having been deeply influenced by the Italian naturalist approach to filmmaking.

Back in London in 1965, Mr. Ové studied at the London School of Film Technique (now the London Film School).

Over his long career he worked extensively in film and television. His documentary about the Bhopal gas leak in India that killed at least 2,000 people, “Who Shall We Tell,” aired in 1985.

A feature film, “Playing Away” (1987), is an amiable comedy of cultures gently clashing when a West Indian cricket team from London is invited to a match in a quaint and insular fictional Suffolk village. Vincent Canby of The New York Times called it a “movie about the comic pretensions of social and political organisms — the kind of community-comedy at which British moviemakers have excelled.”

In addition to his son Zak, from his second marriage, Mr. Ové is survived by his daughter Genieve Sweeney, from his first marriage, to Jean Balosingh; a daughter, Indra, from his second marriage; and a daughter, Ezana, and a son, Kaz, from his third marriage, to Annabelle Alcazar, a producer of “Pressure” and many of Mr. Ové’s films. All three marriages ended in divorce.

Mr. Ové, left, with the writer James Baldwin in 1984 at the opening of the exhibition “Breaking Loose,” a retrospective of Mr. Ové’s photographic work. via the Estate of Horace Ové

In 2022, Mr. Ové was knighted for his “services to media.” In 2007, he was made a commander of the British Empire; while he was in a taxi on the way to the palace for the ceremony, Mr. Ové pulled out a CD of James Brown’s funk anthem “Say It Loud — I’m Black and I’m Proud,” and asked the African cabby to play it at full volume, which he was delighted to do.

“I’m always interested in characters,” Mr. Ové told the Black Film Bulletin in 1996. “I’m interested in people that are trapped, Black, white, whatever race: That is what attracts me to the dramatic film, the trap that we are all in and how we try to get out of it, how we survive and the effects of that trap.”