From Wikipedia

Last Stand Of The 300

In 480 B.C, during the Greco-Persian Wars the Persian Empire lead by Xerxes I of Persia fought the Greeks city-states forces at the pass of Thermopylae in central Greece. This battle become known as the Battle of Thermopylae. The only thing stopping the Persians, was an army led by King Leonidas I & his 300 Spartans, the greatest soldiers the world has ever known. Vastly outnumbered, the Greek Spartans held up the Persians advance for six days, until they were overrun by Persian forces. The film also focus on the lead up to the Battle of Thermopylae revealing that the Greeks might have play a part in the Ionian Revolts in Asia Minor in 499 to 493 B.C. Its brings its viewers into understanding ancient warfare when the documentary focus on the naval battle around Thermopylae, strategic & tactical considerations, and the aftermath of the battle which lead to the burning of Athens and Greek victories in battles such as Marathon & Plataea.