The Spartans (documentary) the Spartan constitution into the militarised state we know of today. Homosexuality among men and boys was mandatory. The training of Spartan youths is explained, from their enrollment in the Agoge system right through to their attainment of citizenship. The class structure of the Lacedaemonian state (Helots, Perioeci, and the soldier-citizens themselves) is also covered. The episode ends with the battle of Thermopylae, in which 300 Spartans, including their king, Leonidas, were killed in action defending Greece from a Persian invasion. Part 2 opens with the retreat of the Persians, after Thermopylae and the battle of Salamis. Athens, which had
Gauls army, defeated Bolgius and repelled the invading Gauls. In the second Gaulish invasion of Greece (278 BC), the Gauls, led by Brennos, suffered heavy losses while facing the Greek coalition army at Thermopylae, but helped by the Heracleans they followed the mountain path around Thermopylae to encircle the Greek army in the same way that the Persian army had done at the Battle of Thermopylae in 480 BC, but this time deafeating the whole of the Greek army. After passing Thermopylae the Gauls headed for the rich treasury at Delphi, where they were defeated by the re-assembled Greek army. This