"The 300 Spartans" is a 1962 film retelling the story of the Battle of Thermopylae (Greek: Μάχη τῶν Θερμοπυλῶν, Máchē tōn Thermopylōn) that took place in August or September 480 BC. For its time it is a pretty good dramatized account of the events surrounding the battle - unlike the graphic novel version "300". Both films draw attention to the small number of Spartan hoplites who, against overwhelming odds, sacrificed their lives to defend Greece. Despite the title, however, the earlier film shows how an alliance of ancient Greek city states (poleis, sing. polis), led by King Leonidas I of Sparta, fought the army of Xerxes I over the course of three days, during the second Persian invasion of Greece.
Background The first Persian invasion of Greece was actually two distinct campaigns beginning in 492 BC. The invasion was ordered by the Persian king Darius the Great primarily to punish the city-states of Athens and Eretria who had supported the cities of Ionia during their revolt against Persian rule. Incurring the wrath of Darius, the Great King saw the opportunity to extend his empire into Europe, and to secure its western frontier. Darius' venture ended in defeat with the decisive Athenian victory at the Battle of Marathon in 490 BC.
Thermopylae The Persian army[1] arrived at the pass in late August or early September but were held by the vastly outnumbered Greeks for seven days. The actual fighting, however, only lasted three days. For two full days the small force led by King Leonidas blocked the only road by which the massive Persian army could pass. After the second day, a local resident named Ephialtes betrayed the Greeks by revealing a small path used by shepherds that allowed the Persians to outflank the Greeks. Leonidas, aware of the danger, dismissed the bulk of the Greek army but remained to guard their retreat with 300 Spartans[2] and 700 Thespians[3]. This small rear-guard fought to the death in one of history's most famous last stands.
Notes:
2. In August 480 BC, Leonidas marched out of Sparta with a small force of 1,200 men (900 helots and 300 Spartan hoplites). Herodotus explains the full Spartan army delayed its advance until completing the traditional Karneia festival (held in honour of Apollo Karneios). Leonidas' force was sent ahead to strengthen the Allies' resolve and to reassure the other Greeks that the full Spartan army was on its way.
3. Others contingents also remained, including the 900 helots of the Spartan's and 400 Thebans; most of the Thebans later surrendered.