With Wednesday's announcement that the former Beatle and his second wife, Heather Mills McCartney, have separated, speculation immediately turned to the financial settlements surrounding the end of their four-year marriage.
"She could get a huge chunk of his wealth," said Patricia Hollings, a divorce specialist with the London legal firm Finers Stephens Innocent. Hollings said that Mills McCartney's relatively young age — she is 38 — and the fact that they have a child, combined with McCartney's "staggering" wealth and celebrity status, have the potential to push the settlement into the stratosphere.
On Wednesday, McCartney, who turns 64 next month, posted a message on his personal Web site saying that he was upset over suggestions that Mills McCartney had simply married him for his fortune, estimated to be $1.5 billion.
Mills McCartney maintains that she volunteered to sign a prenuptial agreement, but the former Beatle's business sense was apparently blunted by love, CBS News correspondent Elizabeth Palmer reports for The Early Show.
"Heather Mills can apply for all the range of financial relief, from maintenance, pensions, lump sums, the whole lot," said divorce lawyer Vanessa Lloyd Platt.
The couple did not have a prenuptial agreement, Mills McCartney said in a Vanity Affair interview in 2002.
"It's been suggested that she married me for the money and there is not an ounce of truth in this," McCartney said in the posting. "She is a very generous person who spends most of her time trying to help others in greater need than herself. All the work she does is unpaid so these stories are ridiculous and completely unfounded."
The couple issued a joint statement insisting their split was friendly — but said that intrusions by the media made it difficult to sustain their relationship.
"Having tried exceptionally hard to make our relationship work given the daily pressures surrounding us, it is with sadness that we have decided to go our separate ways," the couple said. "Our parting is amicable and both of us still care about each other very much."
McCartney and Mills McCartney married in June 2002, four years after his first wife Linda McCartney died of breast cancer. Linda and Paul McCartney married in 1969, and had three children — Mary, Stella and James.
That marriage was one of showbiz's most enduring unions; after Linda McCartney's death, a family spokesman said they "never spent a night apart in the 30 years that they have loved one another."
McCartney and Mills McCartney met at a charity event in 1999, and their relationship immediately made tabloid headlines, not simply because of the difference in their ages but also because of the supposed disapproval of McCartney's children. There were also stories about rowdy arguments between the pair.
"Sir Paul is one of the most if not the most famous musicians in the world," Fiona Cummins, Daily Mirror Gossip Columnist told CBS News. "And presumably Heather found it difficult to cope with his fame."
She must also have found it difficult to step into the shoes of Linda McCartney. But it was barely two years after Linda died of breast cancer that Paul told Hannah Storm of The Early Show that he'd found someone else.
"Someone like myself, you know, is very lucky to get a sort of second chance really, because after having lost Linda, which was such a tragedy in my life, I wasn't sure whether I would find a good woman again," he said.
"It's great to be in love, and she's a great support. She's a pretty cool gal," McCartney said.
Mills McCartney has also been accused of meddling in her husband's career — such as the dismissal of his longtime publicist Geoff Baker — and even of influencing him on issues as diverse as dying his hair and plastic surgery.
At one point, McCartney felt forced to defend his wife publicly. In a statement on Mills McCartney's personal Web site, McCartney posted a note blasting the media and denying the rumors, including suggestions that his children disliked their new stepmother.
Mills McCartney is a former model and a vociferous animal-rights campaigner who recently traveled with McCartney to eastern Canada to fight that country's seal hunt.
On that trip, they appeared happy and professional, an Associated Press reporter who accompanied them said.
In 1993, Mills' left leg was amputated below the knee after a motorcycle accident, and she became active in campaigning to remove and ban landmines.
She has responded in kind when it comes to public support of issues McCartney cares about, and in March she accompanied him to an ice floe off the coast of Canada to take a stand against the annual fur traders' hunt of baby seals.
But not everyone was convinced this was as selfless as it seemed, Palmer reports. McCartney's children from his first marriage were said to have disliked Heather from the start.