Based on Frank Miller's graphic novel, "300" is very loosely based the 480 B.C. Battle of Thermopylae, where the King of Sparta led his army against the advancing Persians; the battle is said to have inspired all of Greece to band together against the Persians, and helped usher in the world's first democracy.
If you liked this movie, you should also see: Mongol: The Rise of Genghis Khan (2007)Gabriel (2007)Carnal Knowledge (1971)Down by Law (1986)The Devil's Backbone (2001)