It was directed by Rudolph Maté and stars Richard Egan, Ralph Richardson, David Farrar, Diane Baker, and Barry Coe.

Outside the hall, Leonidas and Themistocles agree to fortify the narrow pass at Thermopylae with a vanguard force until the rest of the army arrives.

Leonidas decides to march north immediately with his personal bodyguard of 300 veteran men, who are exempt from the decisions of the ephors and the Gerousia, while Leotychidas remains in Sparta.

Leonidas receives word sent by his wife that, by decision of the ephors, the remainder of the Spartan army, rather than joining him as he had expected, will only fortify the isthmus in the Peloponnese and will advance no further.

The Greeks constantly beat back the Persians; following the defeat of most of his "Immortals" (personal bodyguard) by the Spartans and the death in battle of two of his brothers, Xerxes begins to consider withdrawing to Sardis until he can equip a larger force at a later date.

Promising to richly reward the traitorous goatherd for his betrayal (as Ephialtes had expected), an emboldened Xerxes sends his army onward.

The largest establishing scenes of the Persian army entering Greece used many of these soldiers, together with a combined total of several hundred civilian extras, horses, cattle, ox carts, and chariots.

[5] In a contemporary review for The New York Times, critic A. H. Weiler wrote: "In 'The 300 Spartans', filmed in glorious color in authentic settings in Greece and other areas abroad ... this historic highlight has become a standard melodrama.

In its seemingly dedicated efforts, Twentieth Century-Fox, the producer, has come up with an Eastern Western that is plagued by an excess of stilted, stylized dialogue and a minimum of genuine, colorful action that recently has been typical of cinematic forays into our storied past.

... A viewer now can see by what means the Persians and the Greeks annihilated each other, but beyond that it is shallow stuff no more memorable than a weather report, dated 480 B. C."[6] Frank Miller's 1998 graphic novel 300 also depicts the Battle of Thermopylae.