Michael O’Connor designed this beautiful gown for the 2008 film The Duchess, which won the Oscar for Best Costume Design. The gown was worn by Keira Knightley as Georgiana, Duchess of Devonshire. The website for the film documented several of the costumes in detail. Of this gown, O’Connor noted:

The colour of this dress is Tuscan red and is probably the strongest she wears in the film. It was designed for a ball scene where she is drunk and out of control. There were three of the dresses made as the scene involved a stunt. Combined we used 36 metres of silk. Each dress has hand applied green and gold lace. It is adorned with a white rose with yellow stamens.

Once the filming was complete, it appears that this costume – or at least one copy of this costume – went into stock at Angels. For Halloween that same year, model Alexa Chung rented the costume when she hosted a Browns Focus Halloween Party. 

Eventually, the gown went on to be displayed at FIDM and later at an exhibit at Kedleston Hall. You can find more information on this gown, as well as photos of the gown on display at the always excellent Costumers Guide.

This is not the only example of a film costume going on to be rented out for a party. Another great example is Greta Garbo’s heavily beaded gown from Queen Christina.