Last year, it took 275,000 bright pink roses to adorn the Metropolitan Museum of Art for the Met Gala, the biggest night in fashion and one of the biggest concentrations of star power anywhere.

It remains to be seen how the museum’s Great Hall will be decorated come the first Monday in May, but one thing is not in question: those entering it will look spectacular. The theme centers on the late designer Karl Lagerfeld, who made an indelible mark on luxury fashion in his long career at Chanel, Fendi and elsewhere. It is a theme not without controversy — Lagerfeld was known for contentious remarks about everything from #MeToo to curvy bodies.

Want to know what to expect as the big day approaches? Not to worry. We’ve dusted off our annual guide for you here, with some key updates.

WHAT IS THE MET GALA ANYWAY?

It started in 1948 as a society midnight supper, and wasn’t even at the Met.

Fast forward 70-plus years, and the Met Gala is something totally different, one of the most photographed events in the world for its head-spinning red carpet — though the carpet isn’t always red.

We’re talking Rihanna as a bejeweled pope. Zendaya as Cinderella with a light-up gown. Katy Perry as a chandelier morphing into a hamburger. Also: Beyoncé in her “naked dress.”Billy Porter as an Egyptian sun god, carried on a litter by six shirtless men. And Lady Gaga’s 16-minute striptease. And, last year, host Blake Lively’s Versace dress — a tribute to iconic New York architecture — that changed colors in front of our eyes.

Then there’s Kim Kardashian, bringing commitment to a whole other level. (It’s reasonably safe to expect her again this year, because why wouldn’t she be coming?) One year, she wore a dress so tight, she admitted she had to take breathing lessons beforehand. Two years ago, she wore a dark bodysuit that covered even her face. But then last year she truly stole the carpet, showing up in Marilyn Monroe’s actual, rhinestone-studded “Happy Birthday, Mr. President” dress (borrowed from Ripley’s Believe It or Not! museum), changing the minute she got inside to protect it. There was controversy later over suspicions, denied by Ripley’s, that she’d caused some damage. But still — that was an entrance.

It’s important to note that the party has a purpose — last year, the evening earned $17.4 million for the Met’s Costume Institute, a self-funding department. Yes, that’s a heckuva lot for a gala. It also launches the annual spring exhibit that brings hundreds of thousands of visitors to the museum.

But it’s the carpet itself that draws the world’s eyes, with the guest list — strategically withheld until the last minute — featuring a collection of notables from movies, music, fashion, sports, politics and social media that arguably makes for the highest celebrity wattage-per-square-foot of any party in the world.