From the glitter of its golden age to the blockbusters of more recent times, Hollywood has long been a byword for glamour. But while its stars have always been feted, and its directors honoured, one of the most powerful elements of any movie has often been left to languish in the closet. In Hollywood Costume at London’s Victoria and Albert Museum, however, it has been promoted to its proper place as a vital part of the storytelling process.

More than 100 iconic costumes, created over a century of film-making, are featured here. And not all are glamorous. Classics, such as Dorothy’s gingham dress from The Wizard of Oz and Scarlett O’Hara‘s dress from Gone With the Wind, sit side by side with more recent costumes, including Meryl Streep’s outfits from The Iron Lady.

There is the gown Elizabeth Taylor wore as Cleopatra, Audrey Hepburn’s black-and-white dress from My Fair Lady, Robert De Niro’s shorts and leopard print robe from Raging Bull, and the iconic outfits worn by Dan Aykroyd and John Belushi in The Blues Brothers. We also see Keanu Reeves’ costume from The Matrix and Russell Crowe’s combat armour from Gladiator.

The costumes are united in one purpose: they have all played key roles in setting the scene of a movie. They are not fashion items; they are tools of the fantasy trade.

The exhibition offers a tantalising glimpse behind the scenes of early Hollywood, when actors often wore their own clothes; Charlie Chaplin apparently scavenged an outfit for the Little Tramp, which became his most iconic character, from a communal dressing room. As the power and wealth of the studios grew, so did the lavishness of the costumes - though this was not always accompanied by appropriate ways of conserving them.

Over the years they have been pulled apart, reconstructed for new roles, rented out and even dumped and burned. The collection owes much to actress Debbie Reynolds and a handful of other Hollywood veterans, who became determined to save them.

There is food for thought for design students, but also for historians: this glorious collection not only documents Hollywood but paints an evocative picture of the creativity that built California.

Hollywood Costume runs from 20 October to 27 January. www.vam.ac.uk.