His final film was the Academy Award–nominated "Tale of the Princess Kaguya."

Isao Takahata, who co-founded Studio Ghibli with Hayao Miyazaki in 1985, has died at 82, according to Yahoo! Japan. Takahata was a revered director in his own right, helming such animated classics as “Grave of the Fireflies,” “Only Yesterday,” and “Pom Poko”; he most recently directed “The Tale of the Princess Kaguya,” which received near-universal praise an Academy Award nomination for Best Animated Feature.

Takahata’s career dates back to the early 1960s, when he worked in both the film and television industries in his native Japan. In addition to directing, he also worked as an animator, screenwriter, and producer, with his final credit coming on Michaël Dudok de Wit’s acclaimed “The Red Turtle.” Among his many other accolades, Takahata received a Lifetime Achievement Award from the Locarno Film Festival in 2009.

“Grave of the Fireflies” remains his best-known and most respected work, often appearing high on the list of the greatest — and saddest — animated movies of all time. Roger Ebert went one step further, writing in his four-star review that it “belongs on any list of the greatest war films ever made.”

No cause of death is known as of yet, though Takahata is said to have been in poor health and suffering from a heart condition since last year.

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