It was the first American film by Australian director Fred Schepisi (Roxanne, Mr. Baseball). Additional stars include Nelson's fellow recording artist Isela Vega (as Josephina), plus Mexican American actors Gilbert Roland and Alma Martinez (as Juanita) and such screen veterans as Danny De La Paz (Eduardo) and George Voskovec (Herman Pahmeyer).
A third Texan, William D. Wittliff, wrote the screenplay. He's known now as the screenwriter of TV miniseries Lonesome Dove.
Busey plays Karl Westover, a farm boy who's hiding out in Mexico after accidentally killing his brother-in-law in pre-Civil War Texas. Nelson's the title character, a legendary outlaw who's also got a target on his back thanks to his own father-in-law, Don Braulio (Roland).
Westover learns how to survive the elements from Barbarosa. In the process, he earns the respect of Nelson's hard-nosed and hard-hearted character.
"Like his namesake Frederick Barbarossa, the Holy Roman Emperor who, legend has it, waits in a mountain cavern until the need of his countrymen shall summon him, this Barbarosa is a spiritual figure and a savior, albeit a folksy and modest one," reads the New York Times' 1982 film review. "He helps Karl out of one scrape after another, and he defies death so successfully that once he even rises from the grave."
Though the Charlotte Observer's JoAnn Rhetts ripped Barbarosa upon its release for being "a movie filled with character actors in search of a star," Nelson has an undeniable on-screen presence. As does Busey, who was just a few years removed from his defining role as Buddy Holly and not yet the over-the-top character that's now a pet judge.
The two stars' acting prowesses plus Bruce Smeaton's soundtrack and the gorgeous camerawork of Ian Baker made for a box office profit topping $1.7 million plus a perfect store on Rotten Tomatoes.