The line comes from 300, the 2006 film based on Frank Miller's graphic novel about King Leonidas and his Spartans at Thermopylae. Gerard Butler plays Leonidas, whose speeches and battle cries became some of the film's most quoted moments. As short clips from the film circulated on soundboards and video platforms, this rallying moment was lifted out of its battle scene and reused on its own. It has stayed popular because the film's over-the-top heroic tone fits modern hype edits, sports clips and gaming videos perfectly.