Complex sentence: The clone troopers of Star Wars and the army they composed, the Grand Army of the Republic, are first mentioned in George Lucas's film and the title appears across various other Star Wars media.
Split into simpler sentences: The clone troopers of Star Wars and the army they composed, the Grand Army of the Republic, are both first mentioned in George Lucas's film. The title of "Grand Army of the Republic" for the clone army appears across various other Star Wars media.