Their split may have shocked the showbiz world, but yet more evidence has emerged that Katie Holmes had been planning to leave Tom Cruise for months before making the announcement on June 29.
A new report has claimed that Katie made the decision to fire Cruise's 19-year-old daughter Bella, whom he adopted during his marriage to Nicole Kidman, two months previously as she worked for the actress' clothing line Holmes and Yang.
A source told the Hollywood Reporter that while Bella was stunned by the news, it has all started to make sense in the wake of the divorce announcement.
The source said: 'There was never any trouble between them. Bella called Katie "Mom." She was fired out of the blue, and once Katie filed for divorce, it all made sense.
'This was a carefully planned ambush. Katie didn't want Bella working for her anymore because she was Tom's kid.'
The decision to fire Bella was one of the first attempts Katie made to stand up to Cruise and the religious organisation of Scientology, of which the actor is a very vocal member.
Karen De La Carriere, a former Scientology executive who had been married to Scientology's president Heber Jentzsch, who has been missing for years, told the publication that Katie's move was extremely courageous.
She said: 'This was a very bold move on Katie's part, but at the same time she knows these are different times and she has more support.
'Katie ambushed Tom Cruise and in so doing outwitted some of the most controlling people on Earth.'
Now Katie is said to be determined to do everything in her power to get sole custody of her and Tom's six-year-old daughter Suri.
The actress is said to be terrified that Tom is planning to alienate Suri from her mother in the same way that he has kept Bella and son Connor away from their adoptive mother Nicole Kidman.
Ex Scientologist Marty Rathbun, who left the church in 2004 after 22 years at the top of the organisation, advised Tom to give Katie what she wants if he doesn't want sordid details of their former Scientologist's way of life to be made public.
He said: 'Katie could blow Scientology wide open. If Tom's smart, he won't fight her on anything, even custody. He should just try to settle his way out of it.
'She could press this sole-custody issue and litigate it, and that would be the biggest nightmare in the Church of Scientology's history. It would be a circus they couldn't survive.'
Marc Headley, who was aided by police when he left the church in 2005, said: 'You're either in or out when it comes to Scientology.
'That's why Katie is making custody such an issue in the divorce petition. If you're out, the way she seems to be, they want to cut you off from everyone, including your kids.'
However, TMZ.com are reporting that Tom is determined to ensure the divorce settlement from Katie will see him continue to have 'meaningful, significant contact with his daughter'.
A source close to the negotiations told TMZ.com: 'Suri is the primary concern in Tom's life'.
Meanwhile, Headley, who wrote about his experiences with Scientology in Blown for Good: Behind the Iron Curtain of Scientology in 2009, said that Katie is likely be be followed by representatives from the church in a bid to get information on the actress for the divorce battle - claims that the church has already denied.
However, Headley said: 'Scientology is going to do to Katie what they always do in these situations.
'They're going to put a thousand private investigators on her tail and dig through her garbage and talk to her staff even though they don't have any real dirt on her.'
And De La Carriere added: 'I have no doubt that she's being tailed by them. It's par for the course.'
