Kristen Stewart's stunning transformation into Princess Diana in 'Spencer' trailer is jaw-dropping - Watch

In the trailer, actress Sally Hawkins, who plays an undisclosed role that appears to be a confidant to the Princess of Wales, tells Stewart's character: "They know everything."

Los Angeles: Hollywood star Kristen Stewart looks every inch like royalty as she channels Princess Diana in the first trailer for 'Spencer', an upcoming biographical drama about the beloved royal. Directed by 'Jackie' Filmmaker Pablo Larrain, 'Spencer' is set in 1991 and takes place over the Christmas holiday as Diana (born Diana Frances Spencer) grapples with the decision to end her marriage to Prince Charles. English actor Jack Farthing will play the heir apparent to the British throne, reports variety.com.