LONDON — Think of it as Victoria’s (and Albert’s) secret. London’s Victoria and Albert Museum has peeled back fashion’s layers to expose everything from long johns to lingerie in “Undressed,” an exhibition tracing the hidden history of underwear.

It’s a story about covering up, and also about showing off. For centuries, people have worn undergarments for practical reasons of protection, hygiene and comfort — but there has always been an element of sexuality and drama as well.

“Something we wanted to correct in the exhibition is the assumption that all historical underwear is plain,” researcher Susanna Cordner said Wednesday.

She said early underwear involved a simple cotton or linen garment next to the skin, “but then you would get little fashion flairs and little bits of exhibitionism.”

“Any period of history with underwear there’s an implied viewer — there’s someone else in the room.”

That viewer has often been presumed to be male and the wearer female. The show, which features more than 200 items made between 1750 and the present day, is dominated by women’s undergarments: corsets and crinolines, stockings and shifts, chemises and stays.

They range from cotton drawers worn by the mother of Queen Victoria (the V&A museum is named for the 19th-century monarch and her husband), to a Swarovski crystal-studded bra and thong.

But there are men’s unmentionables, too, including 18th-century shirts, which were considered underwear because they were worn next to the skin —only the collars and cuffs could decently be shown. More recent items include David Beckham boxer shorts and crotch-enhancing Aussiebum briefs.