The film The Eagle is based on Rosemary Sutcliff’s Roman novel The Eagle of the Ninth. It was wrongly claimed in a Guardian newspaper that film Centurion was also based on the book. They published this letter that I sent them:

“The film Centurion is not based upon the book The Eagle of the Ninth, beyond the idea of the disappearing ninth legion (N&Q, 24 March). Award-winning novelist Rosemary Sutcliff’s story is of a young Roman who goes on a quest with his slave Esca to discover the fate of his father’s lost ninth legion, restore his father’s reputation, and retrieve the lost eagle. It is the basis of the film The Eagle of the Ninth, being made by Kevin Macdonald. My evidence for this? I look after Rosemary Sutcliff’s books and legacy, as her onetime godson and cousin.”
(Notes and Queries, The  Guardian)

• More about the film of The Eagle of the Ninth