Al Capone, arguably the most famous gangster ever, has grown into a mythic figure, a sort of cigar-chomping, fedora-wearing, machine gun-wielding, vicious, ruthless monster.

To Deirdre Marie Capone, he was simply Uncle Al.

Technically, her granduncle, he was a bear of a man who taught her how to play the mandolin and passed afternoons in his big house on Prairie Avenue in the Park Manor neighborhood in Chicago where his mother lived, playing record after record.

She recalled only once seeing his darker side, in 1946, when she was 6. In the midst of them cooking and singing, Capone said her granduncle, visiting from his home in Florida, got two visitors. He swapped his apron for a suit coat and put on "a cold, hard look."

"It frightened me," Capone said. "After the men left, he sat with this stone face, and then, all of a sudden, he looked at me, winked, got a big grin on his face and took my hand, and we went back to the kitchen and started cooking and singing again."

This emotional duality of Al Capone is hard to find in Hollywood portrayals of the infamous gangster. Look no further than "The Untouchables" movie or TV show or 1975's "Capone" to see Capone's volatile, scary and formidable nature on display. But these depictions lacked a nod to Capone's softer side and his life off the streets.

On the other hand, Stephen Graham's portrayal of Capone on HBO's "Boardwalk Empire" exposes a Capone that many viewers haven't seen before: A man certainly capable of violence but also a gregarious jokester with an unconditional love for family.

The new season of "Boardwalk Empire," which begins Sunday, is set mostly in Atlantic City, N.J., and centers on Steve Buscemi's Enoch "Nucky" Thompson, a fictional politician and gangster who traffics liquor. This season promises to feature more of Graham's emotionally complex Capone and will introduce Capone's brothers, Frank and Ralph.

"As the 1920s progressed, Al Capone (grew) in prominence as well," series creator Terence Winter said. "Even if you didn't want to pay attention to that, you have to."

Winter also said the show "very consciously" moved one of its main characters, Nelson Van Alden (the lawman turned part-time bootlegger played by Michael Shannon), to Cicero at the end of Season 2.

Jonathan Eig, the Chicago-based author of "Get Capone," said Graham's representation is closer to the real man, in that it shows Capone as "the kind of person that you would not mind sitting down next to in a bar."

Graham "captures a lot of Capone's charm and humor," Eig said. "Even when he is going off on someone, he sometimes has a little smile on his face and he is laughing, and that was true of Capone. He was menacing and he was definitely frightening and dangerous, but at the same time he wanted people to see him as a likable guy, and he did have a sense of humor."

Deirdre Marie Capone agreed: "Starting in the last season, they softened (Capone) and made him more human, because he was human and complex."

Speaking from his home in Leicestershire, England, Graham talks in a Scouse accent that comes as a surprise to ears that have only heard him in "Boardwalk" or his turns in "Gangs of New York" and "Public Enemies," a film for which he spent a month or so in Chicago. "I loved the steaks I had in Chicago," he said. "The people, too, I found the people very friendly and accommodating."

Graham said he likes portraying Capone for the same reasons he liked depicting those other mobsters.

"Those people to me are very interesting to play," he said. "They are very interesting characters, and I like the paradox in them kind of people, where, on one level, they try and lead a normal life, and underneath it they are kind of sociopathic or psychopathic. Which is great to play because it is a million miles removed from me, and I am never going to play Mr. Darcy. It's great to be able to play these characters and the complexity of the characters."

Part of the reason "Boardwalk Empire" shows a different sort of Capone could be because the series presents him as a younger man, before he was the "don" of Chicago. "Rather than have Capone be the Capone we all know and love, we see him as a kid when people didn't know his name. They would just say the chubby kid driving the truck," Winter said. "In the pilot he is introduced as (Chicago gangster) Johnny Torrio's driver, and when he finally introduces himself as Al Capone, you realize you are looking at a teenage Al Capone. For me it was much more interesting to explore that guy and see his development and eventually arrive at the Capone we all recognize."

Season 4 is set in 1924 and will "include a lot of action dealing with the Cicero mayoral election," Winter said. The show will also explore the relationship between the three Capone brothers.

"They are like baby wolves," said Domenick Lombardozzi, the actor who plays Ralph Capone. "They are like wolf cubs. They are young, they laugh, they giggle, but they are very dangerous."

Graham said he depicts Capone as though the violence was a necessary part of the job, conditional to taking care of his family.

"He will leave the house and go to work, and it just so happens that his work is, you know, being a gangster," Graham said. "It's killing people, it's running brothels, it's moving booze all over America, and that is just his job, but what I really like to play with him is that double edge, that paradox if you like, that when he goes home … when he closes that door, he is Al Capone, the loving husband and the loving father."

This season will include historical events that will weigh heavily on Capone. (We won't spoil it for you here, but a Google search of the 1924 Cicero mayoral election will provide insight.)

"You get to see an actor who is able to open up something inside of himself and just unzip himself," said Morgan Spector, the actor who plays Frank Capone, of Graham in the fourth season. "You get to see him let all this pain and vulnerability come out, and it is just gorgeous."

When Graham was in town filming "Public Enemies," the bartender at the Green Mill Cocktail Lounge, the Uptown jazz bar that was a supposed haunt of Capone's, led him down into the series of tunnels under the bar that gangsters are said to have used to move then-illegal liquor.