Thumbs up on Benedict's performance in
The Other Boleyn Girl.
His part is small, but very poignant. Some of the best scenes are his and they're cut from the movie. You can see them in the Deleted Scenes section of the DVD.
SOME SPOILERS if you haven't seen the movie.
He plays Mary Boleyn's husband, newly married and they're innocent and very happily wed, just to have the king visit and take a shine to Mary ordering her to the court along with her husband. Since these are 'royal appointments' and the Boleyn men are ruthlessly ambitious, they railroad Benedict's character into accepting the position with him knowing full well what's going to happen. And he's heartbroken about it.
Now the Mary character goes the palace and flattered by the king's attention and lust, decides she's in love with the king and forgets about her husband and doesn't care when the king sends him away from court on an assignment, laughing about her inability to tell the king what to do.
Then in the deleted scene, when Mary returns home to her husband with her illegitimate child, she finds out that while she's been involved in a torrid lust affair and fighting with her sister over the king, her husband has been consumed with guilt, still in love with her. Benedict's acting is amazingly sincere and I tell you I was crying at that scene. I wish they'd put that scene in the movie. It gave real heart to the movie that isn't there otherwise, showing the emotional cost of having an affair and made quite clear that Mary herself is not an innocent victim anymore. She's just as callous and cruel in love as anyone at the Court.