Damian Lewis has been researching an upcoming role with a low-key visit to a university library.
The Homeland star is to play opposite Nicole Kidman as the lover of Gertrude Bell in director Werner Herzog's Queen Of The Desert, due for release next year.
Bell was a British traveller, writer, diplomat and spy in the Middle East in the early 20th century.
Lewis visited Newcastle University's Robinson Library to view the Gertrude Bell Archive, a collection of her personal papers, photos and diaries.
Included are letters to and from his character, Major Charles Doughty-Wylie, a married man who had an unconsummated affair with Bell.
News of Monday's visit emerged today when the university posted a photo on its Twitter feed of Lewis posing with a librarian.
Heart-throb Robert Pattinson will also appear in the film as Lawrence of Arabia.
Bell was born into a family of wealthy industrialists and lived in Washington New Hall in what was then County Durham. She died in 1928.
Staff at the library said Lewis was "extremely nice" and offered to pose for pictures during the flying visit.
University librarian Wayne Connolly said: "The character he plays in the new film was considered the love of Gertrude Bell's life. Charles Doughty Wylie was married and they had an unconsummated affair but it's believed he is the reason Gertrude Bell never wed.
"Damian was extremely interested in our archive as it contains correspondence between them and was able to give him a unique perspective on their relationship."