Boxing legend Jake LaMotta, the onetime middleweight champion of the world who was played by Robert De Niro in 1980’s “Raging Bull,” died Tuesday, his fiancee told the Associated Press. He was 95.

LaMotta passed away in a Miami-area hospital from complications of pneumonia.

"I just want people to know, he was a great, sweet, sensitive, strong, compelling man with a great sense of humor, with eyes that danced," his fiancee told TMZ.

De Niro told Fox News of LaMotta's passing, "Rest in peace, champ."

LaMotta's agent also told Fox News, "Working for the champ for almost 20 years was an honor. Jake was funny and very sweet. Heaven now has a BULL!"

The International Boxing of Fame, which inducted LaMotta in 1990, revealed he began boxing at a young age when his father made him fight other neighborhood kids in The Bronx to entertain adults. His aggressive style earned him the nickname “The Bronx Bull.”

The aspiring fighter turned pro in 1941 at age 19. A six-fight series with Sugar Ray Robinson defined his career. He handed Robinson his first defeat in 1943. He lost the middleweight title to him in what became known as the St. Valentine's Day Massacre.

In the fight before he lost the title, LaMotta saved the championship in movie-script fashion against Laurent Dauthuille. Trailing badly on all three scorecards, LaMotta knocked out the challenger with 13 seconds left in the fight.

On June 16, 1949, he became middleweight champion when Marcel Cerdan couldn't continue after the 10th round.

LaMotta later said, “I fought Sugar Ray Robinson so many times it’s a wonder I don’t have diabetes.”

The fighter, known for a sturdy chin that allowed him to absorb significant amounts of punishment, retired in 1954 with a record of 83 wins, 19 losses and 4 draws. 30 of his wins came via knockout.

LaMotta was married six times, most famously to Beverly “Vikki” Thailer. They wedded in 1946 when she was 16. The couple divorced in 1957 and she later appeared in a nude pictorial for Playboy at age 51. LaMotta joked, “She always complained she had nothing to wear. I never believed her until I saw her in Playboy.”

Both of their sons died in 1998. Vikki later passed away in 2005 at age 75.

In 2012, LaMotta became engaged to 62-year-old actress Denise Baker, who previously collaborated with him on a cabaret show.

The 1980 film "Raging Bull" was based on LaMotta's memoir. Actor Robert De Niro won an Academy Award for it.

The Associated Press contributed to this report.