Mother Angelina

Now 32, she is keen to stress that motherhood is of more importance to her than maintaining the Brangelina brand.

By the time the kids are old enough to really understand all this, hopefully we will be less in the public eye," she says.

"We will do fewer films, we will not be that couple."

It was Mariane's plight as a mother-tobe, she says, that really touched her. "I had just been through pregnancy and I was highly aware of how beautiful that time should be for a woman.

I remember so clearly the moment of giving birth and looking at Brad and the love in that room and the hope for the future.

For her to lose all that and have to suffer as much as she did and then to have no self-pity is just extraordinary.

I met a great friend during this film and she and her little boy continue to teach me about the world."

Adding to the scepticism, there has been outrage from black groups in America that Jolie should play Mariane, who is of mixed Afro-Cuban and Dutch race.

Allegedly, the actress wore make-up to darken her skin - this has not been confirmed - and the film has been cited as an example of Hollywood discriminating against black actresses and accused of obscuring the Pearls' interracial marriage.

She's clearly aware of the potential criticism, and those regarding Pitt's involvement, too (he has also helped produce Martin Scorsese's The Departed and the forthcoming adaptation of The Time Traveler's Wife, through Plan B, the film company he set up, originally with Jennifer Aniston).

"I was very nervous about this film
because having your partner producing can sound like a good idea but can also make the pressure much harder.

To do right by him - and by Mariane - became a pressure that I lost sleep over."

In the event, Jolie's performance satisfied Mariane Pearl herself and Jolie's authentic rawness in the part goes some way to dismissing the idea that the film is her vanity project.

Sporting a wig of short black curls, a fluid French accent and - five months after giving birth herself - a pregnancy bump, she adapted well to Winterbottom's fast hand-held film-making style, already seen to such powerful effect in Road to Guantanamo and In This World.

She is cool and collected throughout, which makes her shrieks at the news of Danny's death all the more heartbreaking.

Jolie's howls of despair alone in the bedroom morph in the next scene into her howls of pain in the delivery room of a hospital where she gives birth to her son, Adam.

"I couldn't get my head round how to play the scene," she recalls.

"I felt it would be indecent to ask Mariane to tell me exactly how she received the news or how she cried.

We all felt horribly sad the night we filmed it.

A man was killed in such a brutal way and this little boy we had all met on the set had lost his dad. So those sounds sort of happened organically."

She needed a bit more help with the birthing scene, she explains.

Like most Hollywood mothers, Jolie had a Caesarian when she gave birth to her daughter, Shiloh, a year ago last May.

"Michael [the director] had to try to explain labour to me because he was with his wife when she had children.

It was very funny having a bunch of men explaining how to scream at the top of my lungs in a quiet floor of a real hospital in India.

We were all screaming back and forth at each other - it was bizarre."

It has been an emotional 12 months for Jolie, however you look at it.

The death of her mother, Micheline Bertrand, from cancer earlier this year left her distraught.

Bertrand and Jolie's father, the actor Jon Voight, separated when she was one, and Jolie and her brother James Haven were brought up by her mother.

She attributes her worryingly thin figure to the trauma she has gone through.

"Someone saying to me that I'm thin is not a compliment," she says.

"I've always been lean and this year I lost my mom and I've gone through a lot.

I have four kids and I finished breastfeeding - it's been hard to get my nutrition back on track.

Instead of people saying I look like a person dealing with something emotionally, they assume it's because I want to fit into skinny jeans."

Her mother was clearly an inspiration.

"Both my parents were very focused on charity and I was always raised by my mom to see the joy she had in doing things for others," she says, as if to stress that her benevolent globe-trotting is a natural continuation of her own upbringing, rather than a way of assuaging Hollywood guilt or drawing attention to herself.

Even through the period of her mother's illness, Jolie remained estranged from her father and the two haven't been in contact since 2002 when Voight said on US television that he wanted her to "get help" for "serious mental problems".

"I am hoping my relationship with my father will be more private in future," Jolie says.

"At the end of the day, we both wish the best for each other and we'll try to start communicating in some way."

Acting was always in Jolie's blood.

Voight, of course, was a major film star when she was born, Bertrand was also an actress and Jolie's brother, two years her senior, studied film-making.

She began studying acting at the age of 11 at the famous Lee Strasberg Theatre Institute in New York, having made her film debut at the age of five in the 1980 comedy Lookin' to Get Out, with her father.

Her teen years were spent acting in music videos and modelling, but she returned to the big screen in the long forgotten Cyborg II: Glass Shadows when she was 18 in 1993, moving on to cyberthriller Hackers (1995) with young British actor Jonny Lee Miller - and a brief marriage to him from 1996 to 1999.

Her career took off in the late Nineties with roles in small films such as Foxfire and Playing By Heart, and two notable TV performances in George Wallace and Gia for which she won back-to-back Golden Globes.

By 1999, when she won an Oscar for Girl, Interrupted, Jolie was a tabloid legend, making headlines for her unpredictable behaviour, penchant for tattoos and revelations about her bisexuality-Her marriage to the equally eccentric-Billy Bob Thornton in 2000 sealed her fate as a media icon, not exactly quelled by the fact that the two carried vials of one another's blood around their necks.

The couple separated in 2002, and Jolie was by then starring in major blockbusters like Gone in 60 Seconds and Lara Croft: Tomb Raider, which established her arguably as the first female action star.

Not that all the films were hits. She racked up her fair share of duds: Original Sin, Beyond Borders, Life Or Something Like It and Alexander.

After shooting Tomb Raider in Cambodia, Jolie made trips to the global hotspots of Sierra Leone, Tanzania and Pakistan, and was appointed Goodwill Ambassador for the United Nations High Commissioner for Refugees.

In 2002, she adopted a seven-month-old Cambodian orphan whom she named Maddox.

Then in 2004, she stepped in for Nicole Kidman in the action thriller Mr and Mrs Smith and met Brad Pitt.

The romance between the two was downplayed while Pitt extricated himself from his marriage to Aennifer Aniston. Sympathies at the time lay with Aniston, and Jolie had to fend off accusations of being a husband-stealer-Angelina, man-eater" ran one headline.

The pair's bond soon became obvious and Pitt started accompanying Jolie on her missions to Third World countries.

They adopted Zahara from an Ethiopian orphanage in 2005, had their biological child, Shiloh, last year, before earlier this year adopting a three-year-old Vietnamese orphan whom they named Pax.

"Pax is a great kid," she says.

"When we first met him, we thought he was really shy and quiet but after two days at home we've discovered that he is one of the loudest members of the family."

Jolie loves talking about her children and their backgrounds and encourages them to remain loyal to their origins (Pax and Maddox are both regularly visited by Vietnamese and Cambodian women to keep up their native languages-She says that Pitt's parents have been very welcoming of all the children.

"When I first met them, I came in with two adopted children from other countries and I didn't know how they were going to be. But they are equally loving with them."

So how many more are the Jolie-Pitts planning to adopt?

"There are certain kids on the periphery that we want to help through school, whose lives we are starting to be involved in as well," she says.

"In our home it is all about how much we balance making sure that everybody has individual time, and right now four of them have very special daily individual time.

We never want to have so many kids that we can't do that."

In the meantime, Jolie hasn't stopped working on movies.

After A Mighty Heart, she will appear in the action-adventure Wanted opposite James McAvoy and Morgan Freeman, which she completed this summer; as the voice of the Queen of the Darkness in animated fantasy Beowulf; and under the direction of Clint Eastwood in The Changeling, the true story of a mother whose son was kidnapped in 1920s Los Angeles.

"I take films very seriously," she insists.

"I love being able to tell a good story or just to entertain, and I don't look down upon it.

It's just that at the end of the day, when I die, I feel that the more significant contribution to have made would be to save a life or change a law that's going to affect people and their children and their country and their rights in the future.

"I want to raise children who will be good people and be a positive influence in this world.

Everything else I have been able to do in my life through entertainment has certainly helped facilitate the other.

I do love being an artist but it's not the core of who I am as a human being.

I would say being a mother comes first."

The future doesn't look so bad for the rainbow brood.

A Mighty Heart opens on 21 September.