Sienna Miller as Anastasia DeCobray / Ana Lewis / The Baroness The sister of Cobra Commander and a spy. Years earlier, The Baroness was going to marry Duke, but he left her at the altar, due to his guilt over her brother 's apparent death. Miller auditioned for the part because it did not involve "having a breakdown or addicted to heroin or dying at the end, something that was just maybe really great fun and that people went to see and actually just had a great time seeing. '' Miller prepared with four months of weight training, boxing sessions and learned to fire live ammunition, gaining five pounds of muscle. She sprained her wrist after slipping on a rubber bullet while filming a fight scene with Rachel Nichols.
who plays anna in gi joe rise of cobra
Sienna Miller