Hollywood heavyweights Angelina Jolie and Brad Pitt have announced their relationship is over after 12 years together, prompting many to speculate on exactly what tore the loved-up duo apart.

Jolie’s filing reveals they, like many Tinseltown couples, had “irreconcilable differences”.

Some reports suggest these differences arose from Jolie’s concern about Pitt’s parenting methods, while her lawyer claimed the decision was made “for the health of the family”.

Pitt, meanwhile, said in a statement to People he was “very saddened” by the divorce and emphasised the importance of his kids’ wellbeing.

‘Something very serious must have happened’

Those who know the family were shocked by the news – Pitt’s good friend George Clooney was forced to find out from a CNN reporter, while Jolie’s estranged father Jon Voight told Inside Edition he “didn’t know” what caused the separation.

“It’s very sad,” Voight said. “Something very serious must have happened for Angie to make a decision like this.”

So what went wrong only two years into their seemingly blissful marriage?

What the court documents reveal

Jolie’s divorce petition, filed on September 19, revealed she is not seeking spousal support but wants sole physical custody of their six children and for Pitt to have visitation rights.

Jolie and Pitt with children Zahara and Maddox in 2006. Photo: Getty

However, she is happy to share legal custody with Pitt, meaning they would both be responsible for all decisions pertaining to their children.

Peter Walzer, the lawyer who represented actress Katie Holmes in her divorce from Tom Cruise, told Reuters it was unusual to seek sole physical custody and it suggested Pitt was not competent to be a parent.

“It’s an insult,” Walzer said.

According to TMZ, Jolie became “fed up” with Pitt’s consumption of weed and alcohol and his “anger issues”, leading her to be concerned over his interaction with their children.

Jolie’s petition also lists separate property including “miscellaneous jewellery and other personal effects”, and earnings from and after the separation.

It indicates that separate and community property assets are yet to be determined.

A year of turmoil

A source told People Pitt’s frequent trips to the couple’s estate in the south of France this year may have been an early sign of discontent.

According to the source, Pitt would often “flee” to Chateau Miraval after the pair argued, staying for a couple of days at a time.

The couple’s sprawling property in Correns, France, boasts olive groves, vineyards and a private lake. Photo: Getty

The stars got married at Miraval in August 2014 and spent their honeymoon filming their movie By the Sea on location in Malta.

The movie was released in late 2015 to terrible reviews and Jolie admitted it was stressful to portray a couple in the midst of a relationship breakdown while celebrating her honeymoon.

“To be clear: we have fights and problems like any other couple,” she told The Telegraph.

“We have days when we drive each other absolutely mad and want space, but the problems in the movie aren’t our specific problems.”

The pair have spent lots of time apart over the last year as Pitt filmed Allied in Europe and Jolie filmed her Netflix documentary First They Killed My Father: A Daughter of Cambodia Remembers in Cambodia.

A recent New York Times profile of Pitt notably avoided all mention of Jolie or their children.

The couple in their 2015 film By the Sea.

The kids

Undoubtedly the biggest victims of the split are the couple’s six children: Maddox, 15, Pax, 12, Zahara, 11, Shiloh, 10, and twins Vivienne and Knox, 8.

The pair wed in an intimate ceremony in France in 2014.

The kids were one of the main reasons Jolie and Pitt decided to get married in the first place – they originally wanted to wait until same-sex marriage was legalised in the United States.

“We made this declaration some time ago that we weren’t going to do it till everyone can,” Pitt told The Hollywood Reporter in 2012.

“But I don’t think we’ll be able to hold out … It means so much to my kids, and they ask a lot.”

What else is at stake?

Aside from the custody arrangements and wellbeing of their six children, Pitt and Jolie also have a large joint fortune to divide.

While there’s no word on whether the couple signed a prenuptial agreement, experts have commented it’s highly likely they would have.

Their joint net worth is estimated to be nearly $US500 million and they purchased four properties together throughout their relationship.

Divorce proceedings will no doubt have to settle who gets the 1200-acre Chateau Miraval, as well as the money made from the sale of their New Orleans home (it’s been on the market since May 2015), and ownership of their apartment in the Waldorf Astoria Towers in New York.

Pitt and Jolie’s New Orleans home is up for sale. Photo: Zillow