James Packer sold control of his media empire just weeks before he is to marry Erica Baxter in a sumptuous ceremony in France.
Shrouded in secrecy, the wedding is in the final stages of planning and is likely to be held in the French countryside near the Riviera.
Big-name guests such as fellow Scientologists Tom Cruise and Katie Holmes, plus cricketer Shane Warne and broadcaster Alan Jones, are expected at the ceremony tipped to be on June 16 or June 23.
Wedding guests have been sworn to secrecy about the ceremony, which is expected to be performed by a minister of Scientology.
The wedding vows will be chosen from one of five readings by Scientology founder L. Ron Hubbard.
According to Scientology texts, an example of what the minister might say to the couple is: "Now James, girls need clothes and food and tender happiness and frills, a pan, a comb, perhaps a cat. "All caprice if you will, but still they need them."
And to the bride: "Hear well, sweet Erica, for promise binds. Young men are free and may forget. Remind him that you may have necessities and follies, too."
The French wedding is expected to involve a flotilla of Packer-owned or hired luxury yachts to look after guests.
It could be on the same scale as Cruise's star-studded wedding in Italy late last year, at which the Mr Packer and Ms Baxter were guests.
The build-up comes as Mr Packer yesterday sold down his stake in his family-built Publishing and Broadcasting Media Holdings.
Mr Packer will retain a 25 per cent stake in the group, including the Nine Network and ACP magazine titles such as The Bulletin and The Australian Women's Weekly.
Australia's richest man is now intent on turning PBL into a global gaming giant.
But his bride-to-be is more focused on the wedding and the release this weekend of a pop album. Model and singer Ms Baxter has been careful to give nothing away about the wedding while promoting her album Through My Eyes.
She admitted to Jones on his radio show that she's not getting much sleep leading up to the big day, spending hours on its organisation.
"I've been trying to do a lot of it myself," Ms Baxter said.
"I'm hoping to start delegating. It's really hard. I never knew how much organisation goes into it, it's incredible."
Ms Baxter will walk down the aisle with her father, Michael, a solicitor from Gunnedah in northwestern New South Wales.
A big-name performer is expected to entertain guests.
At Mr Packer's first wedding to model Jodhi Meares, superstar Elton John reportedly pocketed $800,000 for the gig.
Ms Baxter's relationship with Mr Packer is not her only high-profile one.
In 1994 she was in a relationship with Australian actor Jason Donovan.
This week, Mr Packer's wealth was estimated at $7.25 billion.