A private performance by Beyoncé, by most measures, would be the highlight of any luxury wedding celebration. But for the wedding of Isha Ambani and Anand Piramal, the children of two of India's richest men, the mega-star's show was merely one act of a welcome party concert.

These aren't just any billionaires; Ambani is the daughter of the presumed wealthiest man in Asia, Mukesh Ambani, who is estimated to be worth $47.3 billion, according to Fortune. Piramal's father, Ajay Piramal, is worth is estimated $4.2 billion.

On Wednesday, the bride and groom, who were childhood friends, tie the knot, wrapping up a week-long celebration that has been rumored to cost as much as $100 million. That would make it the second costliest wedding in history, after the 1981 marriage of Princess Diana and Prince Charles, whose celebrations, which included 27 wedding cakes and intense security measures, reportedly cost $48 million at the time, or $110 million in today's dollars, adjusted for inflation.

A family member of the Ambani's, however, has disputed the number, saying the nuptials have hovered around $15 million.

From beginning to end, it's an been an event that's redefined wedding extravagance and attracted worldwide interest. Various reports provide glimpses of the over-the-top details: Guests were delivered invitations housed in a Dolce & Gabbana box, decorated with chains and lace that could be repurposed as a necklace, said one party-goer. On Saturday morning a 100-plane fleet of private charter jets whisked guests to Udaipur, India's northern lake district known for its royal residences, where they stayed in, of course, five-star accommodations. A custom-built app let guests know the event's schedule.

That evening, 2,000+ guests, including Hillary Clinton, Arianna Huffington and newlyweds Nick Jonas and Priyanka Chopra, were treated to a private concert, which included performances from Beyoncé as well as Bollywood superstars like Aishwarya Rai. Indian weddings traditionally involve several days of celebrations, and that was just the start.

Wednesday's nuptials will take place at Mr. Ambani's home in Mumbai, a 27-floor high-rise mansion which includes a six-story parking garage and three helipads, according to The New York Times.

Photos from the Saturday night event show Beyoncé donned multiple outfits for the 45-minute show.

The guest list included plenty of well-known names, including Hillary Clinton and John Kerry, seen here dancing at one of the wedding's many events.

Clinton was also spotted on a shopping trip with the bride and bride's mother.

Newlyweds Nick Jonas and Priyanka Chopra also were there. The two celebrated their own wedding in India just last week.