In The Lord of the Rings: The Return of the King, Aragorn says, “For Frodo” before charging toward the Black Gate. The brief line identifies his personal reason for taking part in the desperate attack.
The charge is intended to distract Sauron’s forces while Frodo and Sam attempt to reach Mount Doom. Aragorn and the assembled army know they are vastly outnumbered, so the assault is a sacrifice designed to draw attention away from the Ring-bearer.
Viewers sometimes remember the line as “For the Shire” or “For Middle-earth,” because both ideas motivate the defenders. The film’s actual spoken line is the name of Frodo, whose mission determines the fate of the entire story.
The quote appears in Peter Jackson’s 2003 film adaptation, based on J. R. R. Tolkien’s novel. Viggo Mortensen plays Aragorn, while Elijah Wood plays Frodo.