Based on the graphic novel by Frank Miller, 300 tells the heroic story of Spartan king Leonidas (Butler) and 300 of his best warriors as they fight the invading Persian army of King Xerxes in Thermopylae in 480 B.C. Filled with amazing battle sequences straight out of the graphic novel, 300 is a dramatic retelling of a part of Greek history re-interpreted through Frank Miller's work.