Fans have been given their first glimpse into Kristen Stewart’s portrayal of Princess Diana as the first trailer for Spencer has been released.

Spencer is an upcoming biographical film based on the later years of the marriage of Diana Spencer, Princess of Wales (Kristen Stewart) and Charles, Prince of Wales (Jack Farthing).

Directed by Pablo Larraín and written by Steven Knight, it is set to be one of Stewart’s most mature performances to date.

It covers a period in 1991 during Diana’s Christmas holidays with the royal family at Sandringham House in Norfolk, when Diana decides to end her marriage to Charles.

In the trailer, Stewart is seen drifting through lavish corridors and appears to be hiding secrets she is not showing.

“They know everything,” one of Stewart’s aides fearfully tells her.

In a stern but calm response, Stewart delivers two words that appear to encapsulate what this movie is all about: “They don’t.”

Spencer was Diana’s maiden name prior to her marriage to the British royal, which has now been used as the upcoming movie’s title.

“The marriage of Princess Diana and Prince Charles has long since grown cold,” the movie’s synopsis reads. “Though rumours of affairs and a divorce abound, peace is ordained for the Christmas festivities at the Queen’s Sandringham Estate.

“There’s eating and drinking, shooting and hunting. Diana knows the game. But this year, things will be a whole lot different. Spencer is an imagining of what might have happened during those few fateful days.”

Spencer will be released in UK & Irish cinemas later this year following its World Premiere at the Venice Film Festival on 3 September.