Dakota Fanning is to play Princess Margaret in a new film which will explore her teenage years with her sister, the Queen.
The movie, Girls' Night Out, will begin filming later this year, according to film industry bible Variety.
It is inspired by a real-life event in which Margaret and Elizabeth were allowed out of Buckingham Palace for a night to join in the victory celebrations which marked the end of the Second World War in Europe in 1945.
The role of Elizabeth, who became Queen just seven years later, is yet to be cast.
Dakota, 16, is best known for her role as Jane in the Twilight saga, but has also appeared in War Of The Worlds.
The new film is to be directed by US-born and Oxford educated Michael Hoffman, who was behind The Last Station starring Dame Helen Mirren, who landed an Oscar for her portrayal of the monarch in The Queen.
It is being made by Ecosse Films, whose successes have included Becoming Jane and Nowhere Boy, and will be written by Trevor De Silva.
Margaret died exactly nine years ago today at the age of 71.