LONDON (CNN) - It's not quite a royal wedding, but on the scale of hotly anticipated nuptials, it's pretty close.
She is Philippa Charlotte "Pippa" Middleton, the younger sister of Catherine, the Duchess of Cambridge.
He is James Matthews, a millionaire hedge fund manager.
Six years after famously taking part in her sister Kate's fairy-tale wedding, Pippa will take center stage in her own lavish one.
Middleton and Matthews will tie the knot Saturday at St. Mark's Church in Englefield, Berkshire.
It's set to be Britain's wedding of the year.
Prince William, the Duke of Cambridge, and Middleton's big sister, Kate, will be among the guests. And their two children will play starring roles in the ceremony.
Three-year-old Prince George will be page boy, and 2-year-old Princess Charlotte will be a flower girl.
The Duchess of Cambridge has already admitted she is a little worried about how her children will behave. She's "hopeful that they would be good, but you never know at that age," she reportedly told a guest at a Buckingham Palace garden party recently.
Prince Harry is on the guest list.
But most of the details are being kept under tight wraps.
The wedding reportedly will be Scottish-themed, complete with whiskey and bagpipes, Daily Mail reports.
The bride and groom have been spotted in the English countryside, attending to the final details at the 12th-century church where the wedding ceremony will take place.
Just a few miles away is the Middleton estate, where the marquee reception will be held.
Middleton first grabbed the world attention's at the wedding of her sister in 2011 to Prince William.
As maid of honor, her eye-catching, sleek white gown made headlines. And her svelte figure turned her into a celebrity on social media.
And just like that, the overshadowed younger sister shot to fame.
With that celebrity status came opportunity.
The younger Middleton authored a book. She even become a contributor for Vanity Fair.
"It's been a crazy couple of years since my sister's wedding but it's had its upsides and downsides and I just feel really fortunate to be able to build a career as a writer," she said a year after her sister's wedding.
After dating a string of high-society men, 41-year old Matthews, popped the question last summer after almost two years of dating. Matthews' parents are multi-millionaires -- his father, David, was a racing driver-turned-property developer. His younger brother is Spencer Matthews of "made of Chelsea" fame.
Despite all the interest in the couple, the big question is whether Prince Harry's girlfriend, actress Meghan Markle, will be his date.
If Markle attends, it would be the couple's highest-profile outing to date.
And it just may spark rumors of another royal wedding in the wings.