01/02/2012 10:03 GMT | Updated 22/05/2015 10:12 BST

Keira Knightley Is Beautiful In Backless Dress At A Dangerous Method Premiere

Michael Fassbender and Viggo Mortensen.

Michael Fassbender, keira Knightley and Viggo Mortensen at the premiere of A Dangerous Method A Dangerous Method: Michael Fassbender, Keira Knightley and Viggo Mortensen at The Mayfair Hotel.

Look back at Miss Knightley's style evolution in the gallery below:

Shop below at MyDaily Store to find more beautiful backless dresses: