LOS ANGELES (AP) ― Saul Landau, a prolific, award-winning documentary filmmaker who traveled the world profiling political leaders like Cuba’s Fidel Castro and Chile’s Salvador Allende and used his camera to draw attention to war, poverty and racism, has died. He was 77.

Landau, who had been battling bladder cancer for two years, died Monday night at home in Alameda, California, with his children and grandchildren, said colleague John Cavanagh, director of the Institute for Policy Studies in Washington, where Landau had worked for many years.

The director, producer and writer of more than 40 documentaries had continued to work almost until his death. He regularly submitted essays to the Huffington Post and elsewhere, sometimes writing from his hospital bed, according to his son, Greg. He was also working on a documentary on homophobia in Cuba.

Even in his final weeks, as his health was failing, Cavanagh said, Landau would become energized whenever the conversation turned to how people could improve humanity.

“He knew he’d made a contribution and he was happy about that, he was happy, but he wanted to talk about how to make the world a better place,” Cavanagh said Tuesday, recalling an hours-long discussion the two had earlier this year. “When we got into that is when he really got animated and full of life, it was fascinating to see.”

Landau authored 14 books. While most covered issues like radical politics, consumer culture and globalization, one of them, “My Dad Was Not Hamlet,” was a collection of poetry.

His documentaries tackled a variety of issues, but each contained one underlying theme: reporting on a subject that was otherwise going largely unnoticed at the time, whether it was American ghetto life, the destruction of an indigenous Mexican culture or the inner workings of the CIA.

“We tried to take on themes that nobody else was taking on and that were important,” Landau told The Associated Press in July.

His most acclaimed documentary was likely 1979’s “Paul Jacobs and the Nuclear Gang,” which examined the effects of radiation exposure to people living downwind from Nevada’s above-ground nuclear bomb tests in the 1950s. The film received a George Polk Award for investigative reporting and other honors.

It took its name from Landau’s friend Paul Jacobs, who contracted cancer that he believed was caused by radiation exposure. He died before the film was completed.

Landau told the AP one of the documentaries he was most proud of was “The Sixth Sun: Mayan Uprising in Chiapas,” which looked at the 1994 rebellion by the impoverished indigenous people of southern Mexico. Landau traveled to Chiapas to interview, among others, the masked revolutionary leader known as Subcommandante Marcos.

His 1968 documentary “Fidel” gave U.S. audiences one of their earliest close-ups of the revolutionary leader who installed Communism in Cuba. It came about after a brief meeting with Castro, who told Landau he had seen a news report he had done on Cuba the year before.

“He said he liked the film very much and asked me what my next film was going to be,” Landau recalled. “I said, ‘I’d like to do one on you.”’

In 1971, Landau and fellow filmmaker Haskell Wexler traveled to Chile for a rare U.S. interview with Allende, who had just been elected his country’s president and who would die two years later in a military coup.

Although he made more than three dozen films, Landau said he never set out to be a filmmaker.

“I didn’t set out to be anything,” he said in July. “I just fell into it.”

Landau graduated from the University of Wisconsin, Madison, and after moving to San Francisco he was at various times a film distributor, author, playwright and member of the San Francisco Mime Troupe.