The U.S. film production, financing and worldwide distribution company said "The Last King of Scotland" filmmaker Kevin Macdonald is attached to direct "Eagle" as his next feature.
Film4 is co-financing with Focus, which will hold worldwide rights to the movie, excluding British free-TV.
Focus Features Chief Executive Officer James Schamus made the announcement Tuesday.
The project reunites Macdonald with Jeremy Brock, co-writer of "Scotland."
Brock has adapted the "Eagle" screenplay from Rosemary Sutcliff's novel of the same name. Duncan Kenworthy will produce the movie through his Toledo Productions.
Focus described the movie as "a Roman adventure set in the dangerous world of second-century Britain."
"This tale of high adventure, in the hands of this passionate trio of storytellers, is the kind of movie that can and will excite audiences all over the world," Schamus and Focus Features International President Alison Thompson said in a statement.