James Gandolfini, the actor famous for his lead role in mob drama The Sopranos, has died in Italy, according to his managers.

The 51-year-old died yesterday while on holiday in Rome, according to HBO and the actor's managers Mark Armstrong and Nancy Sanders.

It is understood Gandolfini was in Italy to attend the 59th Taormina Film Festival.

In a statement, HBO called the actor a great talent and a gentle and loving person.

Gandolfini played conflicted mob boss Tony Soprano in the groundbreaking HBO series that aired from 1999 to 2007.

His film credits included Zero Dark Thirty and Killing Them Softly, and he appeared in the Broadway production God Of Carnage.

"Our hearts are shattered and we will miss him deeply. He and his family were part of our family for many years and we are all grieving," Gandolfini's managers said.

Gandolfini's performance as Tony Soprano was indelible and career-making, but he refused to be stereotyped as the bulky mobster who was a therapy patient, family man and cold-blooded killer.

After the series concluded with an ending that left viewers guessing, Gandolfini's varied film work also took in comedy, with Armando Ianucci's political satire In the Loop, and voiceover as the Wild Thing Carol in Where the Wild Things Are.

Gandolfini also shared a Broadway stage in 2009 with Jeff Daniels, Hope Davis and Marcia Gay Harden in the celebrated production of God Of Carnage, for which he earned a Tony Award nomination for best actor. He also was in On the Waterfront with David Morse.

In a December interview, Gandolfini said he gravitated to acting as a release, a way to get rid of anger. "I don't know what exactly I was angry about," he said.

"I try to avoid certain things and certain kinds of violence at this point," he said. "I'm getting older, too. I don't want to be beating people up as much. I don't want to be beating women up and those kinds of things that much any more."

Sopranos creater David Chase said: "He was a genius. Anyone who saw him even in the smallest of his performances knows that. He is one of the greatest actors of this or any time. A great deal of that genius resided in those sad eyes."

Lorraine Bracco, who played Tony's psychiatrist Jennifer Melfi in The Sopranos, said: "I had the greatest sparring partner in the world, I had Muhammad Ali. He cares what he does, and does it extremely well."

While Tony Soprano was a larger-than-life figure, Gandolfini was modest and obsessive. He grew up in New Jersey, the son of a building maintenance chief and a school cafeteria worker. After earning a degree in communications, he moved to New York City, where he worked as a bartender, bouncer and nightclub manager. When he was 25, he joined a friend of a friend in an acting class, which he continued for several years.

Gandolfini's first big break was a Broadway production of A Streetcar Named Desire in which he played Steve, one of Stanley Kowalski's poker buddies. His film debut was in Sidney Lumet's A Stranger Among Us in 1992.

Director Tony Scott once praised Gandolfini's talent for fusing violence with charisma, calling him "a unique combination of charming and dangerous".

Gandolfini played a tough guy in Tony Scott's 1993 film True Romance, who beat Patricia Arquette's character to a pulp while offering jarring, flirtatious banter.

It was True Romance that piqued the interest of Sopranos creator Chase, leading to the role that won Gandolfini three Emmy awards.

Gandolfini produced a pair documentaries for HBO focused on a cause he held dear: veterans' affairs.

Alive Day Memories: Home From Iraq in 2007 profiled 10 soldiers and marines who waged personal battles long after their military service had ended.

Four years later, Wartorn: 1861-2010 charted victims of post-traumatic stress disorder from the US invasion of Iraq all the way back to the Civil War.

"Do I think a documentary is going to change the world?" Gandolfini said with characteristic modesty during an interview about the second film. "No, but I think there will be individuals who will learn things from it, so that's enough."

Gandolfini and his wife Deborah, who were married in 2008, have a daughter Liliana, born last year, HBO said. The actor and his former wife Marcy have a teenage son, Michael.