2007's "300" told the story of a small Spartan army that stood up to an insurmountable Persian army. The rebellion didn't go very well. The ending set the stage for a sequel where armies from other Greek cities would band together to face the Persians with better odds. "300: Rise of an Empire" is not that sequel. It tells the story of a small Athenian army that stands up to a different version of the insurmountable Persian army around the same time as the Spartan army. The first film was dumb and violent. The new film is also dumb and violent, with the added failure of being unoriginal. One "300" is more than enough.