Richard Harris, the boisterous Irish-born actor who over six decades played everyone from King Arthur in "Camelot" to Professor Dumbledore in "Harry Potter and the Sorcerer's Stone," died Friday night at a London hospital, according to published reports. He was 72.

Harris died at 7 p.m. London time at University College of London Hospital. The cause of death was not immediately known, but just last week, his agent confirmed that the two-time Oscar nominee was battling Hodgkin's Disease and was undergoing chemotherapy after being hospitalized in August.

By all accounts, Harris was both a distinguished leading man and a rambunctious hell-raiser, rising to stardom in the '50s and '60s with roles in 1967's "Camelot" and 1970's "A Man Called Horse." Harris picked up his first Oscar nomination for his role as coal miner Frank Machin in 1963's "The Sporting Life."

He continued to work steadily throughout the '90s, scoring his second Oscar nomination for 1990's "The Field," before going on to roles in 1992's "Unforgiven" and 2000's "Gladiator," in which he played Marcus Aurelius.

But in an interview with PEOPLE last year, Harris acknowledged that Hollywood had changed since his hard-partying early days with the likes of Richard Burton and Peter O'Toole.

"Peter O'Toole and I had dinner ... and talked about what if we were starting out now," he told the magazine. "We came to the conclusion that if we lived the type of life we lived back then -- as rabble-rousers -- we'd be unemployable by 2001 Hollywood standards."

Even so, his biggest box-office success didn't come until the twilight of his career -- when he signed on to play Professor Albus Dumbledore in the big-screen version of J.K. Rowling's "Harry Potter and the Sorcerer's Stone." (He will also appear in its upcoming sequel, "Harry Potter and the Chamber of Secrets," due out Nov. 15.) Harris had agreed to costar in the film's third installment, "Harry Potter and the Prisoner of Azkaban," which was due to start shooting next March.

He told PEOPLE that he initially balked at the idea of appearing in the "Harry Potter" films. "I run away from commitment," he told the magazine in 2001. "I loathe it." But his only grandchild, Ella, made him decide otherwise. "She called me and told me she'd never speak to me again if I didn't play Dumbledore."

Harris, who was divorced twice (he was married to actress Elizabeth Harrison and model-turned-actress Ann Turkel), is survived by his three sons with Harrison -- director Damien Harris, and actors Jared and Jamie Harris.