LONDON — Britain will celebrate its second royal wedding of the season Saturday, with equestrian star Zara Phillips — eldest granddaughter of Queen Elizabeth II — taking center stage as she marries England rugby stalwart Mike Tindall.

A regal supporting cast is expected as the queen leads her extended brood to Edinburgh, Scotland, for the private festivities. Prince William and Kate Middleton, now the Duke and Duchess of Cambridge, are expected, along with Prince Harry (still single) and bright lights from Britain’s sports and show business worlds.

The nuptials of Phillips, 30, and Tindall, 32, are expected to be far more low-key than William’s wedding in late April, which was watched live on television throughout much of the world. Phillips — who does not carry a royal title — and Tindall prefer to stay out of the limelight when they are not competing.

“It’s the complete opposite end of the royal wedding spectrum,” said Joe Little, managing editor of Majesty magazine. “William and Zara are both the queen’s grandchildren: He’s got the title, he’s going to be the monarch, but Zara thinks of herself more as a sportswoman than as a royal.”

He said Phillips and her fiance go about their daily lives “like regular people” and are generally left alone even by people who recognize them.