Angelina Jolie: Actress, humanitarian and tabloid star

Angelina Jolie and Brad Pitt have become one of the world's most recognisable couples

Despite being a glamorous Hollywood actress whose lifestyle is a tabloid obsession, it is not so surprising that Angelina Jolie should choose to make public her decision to have a double mastectomy by writing about it in the New York Times.

For in recent years the 37-year-old star has made headlines as much for her campaigning and awareness-raising as she has for the films she has made and the man she is with.

In fact, during the nine weeks she underwent the procedures needed to remove both her breasts, she visited the DR Congo to highlight sexual violence in conflict and helped launched a girls' education charity set up by Malala Yousafzai, the Pakistani schoolgirl shot by the Taliban.

It was following the loss of her beloved mother to ovarian cancer at the age of 56 in 2007 that Jolie discovered she carried a "faulty" gene that heightened her risk of getting both breast and ovarian cancer. She decided "to be proactive and to minimise the risk as much as I could".

"Life comes with many challenges," she ended her newspaper article by saying. "The ones that should not scare us are the ones we can take on and take control of."

'Fight to be had'

Angelina Jolie was born in Los Angeles in 1975 to the Oscar-winning actor Jon Voight and his then wife, the actress Marcheline Bertrand.

Angelina Jolie has described her mother, who died from cancer at 56, as an "extraordinary woman"

Within a year of Jolie's birth, her parents split up, allegedly due to Jon Voight's infidelities - an issue that has reportedly strained the father-daughter relationship for many years.

Her relationship with Bertrand was very different. She has described her as "an extraordinary mother" who was "selfless and very kind".

She credits her mother with giving her a love for the movies and a campaigning spirit. Bertrand co-founded an organisation to help Native American people and raised awareness about cancers affecting women.

With acting in her blood, it is perhaps not surprising that Jolie - who had her first starring part at the age of seven - chose to pursue a career in film and enrolled at theatre school.

But her teenage years were marked by periods of depression and difficulties. She has spoken in the past of her experiments with self-harming and drug-taking.

Her professional acting career began in the early 1990s, and she starred in a series of low-budget independent films before landing some award-winning roles. She won an Oscar for best supporting actress in the 1999 film Girl, Interrupted.

As her career took off, she had two short-lived marriages - to the British actor Jonny Lee Miller and the US actor Billy Bob Thornton.

Jolie's life changed in 2001 when she went to Cambodia to film the blockbuster Lara Croft: Tomb Raider.

Not only did it lead to her first child - she adopted an orphaned Cambodian boy Maddox - but she says it was during this trip that she became personally aware of humanitarian issues, and decided she wanted to become actively involved.

Months later, she became a goodwill ambassador for the UN High Commissioner for Refugees - a position she held until she was asked to become a special envoy for the organisation in 2012.

The role has taken her to refugee camps in more than 30 countries, including Sierra Leone, Darfur, Iraq, Afghanistan and Libya.

She has been a speaker at the World Economic Forum in Davos and lobbied on humanitarian issues in Washington. Only last month, she spoke at the G8 summit of foreign ministers in London.

"There is a fight to be had… and it's to look after children, to right the wrongs around the world. And if there is war, or if there are people suffering, or if there are certain situations that are going unnoticed, then you have to do what you can," she has said of her work with the UNHCR.

'Brangelina'

But for the tabloid newspapers and gossip magazines, the fascination lies with Jolie's relationship with fellow Hollywood actor Brad Pitt and their six children.

Angelina Jolie visited the DR Congo with UK Foreign Secretary William Hague in March

She and Pitt met while filming Mr and Mrs Smith in 2005, while he was still married to the actress Jennifer Aniston.

They denied having an affair on set, although Ms Jolie later admitted they "fell in love" then.

"To be intimate with a married man, when my own father cheated on my mother, is not something I could forgive," she explained in 2005.

By 2006, they had adopted an Ethiopian girl, Zahara, and had their first biological child, Shiloh, in Namibia.

A year later, they adopted three-year-old Pax from Vietnam, and in 2008 Ms Jolie gave birth to twins, Knox and Vivienne.

Together the couple - dubbed Brangelina by the press - have lent their names and money to a number of charitable causes.

Jolie's revelation of her double mastectomy comes amid much frenzied speculation over whether the couple are preparing imminently to formally tie the knot.