how did the state of Sparta fall?

OK guys, '300' is not a 100% accurate account of events at Thermopylae.

Frank Miller has said as much, that it is intended to be more a campfire story where the events are magnified in the telling, where the heroes are larger-than-life and the enemies more deadly and numerous than in the prosaic reality. It's more about the process of myth-making than it is about history.

Sparta was a state which could not exist beyond the direct rule of a single city-state (polis) and its immediate vicinity. It was a high-coercion state which was able to survive only through systematic brutalisation of a vast population of serfs (known as helots).

Sparta achieved a brief hegemony over the Greek poleis at the end of the Peloponnesian War, but only succeeded in fuelling resentment at the installation of authoritarian governments in its conquered cities, which soon overthrew their Spartan-backed oligarchs.

Sparta's decline began when they were defeated by the Thebans at Leuctra in 371 BCE. Following Leuctra, Thebes was able to liberate a sizable portion of Spartan territory. The inhabitants, the native Messenians, who had been oppressed as helots, were able to establish their own city-state as a counter to Sparta. Sparta consequently lost a large portion of its agricultural base, and this affected its ability to maintain an elite corps of full-time warriors. This was the first major setback for Sparta in its own territory, and the beginning of its fall from the top tier of Greek poleis.

The Battle of Mantinea in 362 BCE destroyed any chance of a Spartan resurgence. The Thebans deployed their own hoplites in a block 50 ranks deep on their left, while the Spartans and their allies were deployed in a standard flat frontage 12 ranks deep.The Thebans also had a contingent of Thessalian cavalry to protect their flanks, who proved too numerous for the Spartans' allied cavalry. The Spartans never gave much thought to cavalry of their own, preferring to concentrate on close-order infantry tactics.

The huge Theban phalanx was able to smash the Spartan right while cavalry and light troops pinned the Spartan allies' left. The allies broke and fled, but the death of the Theban commander Epaminondas meant that the pursuit was not pressed home as decisively as it should have been.

The death of Epaminondas at Mantinea, combined with the defeat of the Spartans, created an effective power vacuum which Phillip II of Macedon was able to exploit several years later when he established supremacy over the Greek mainland as hegemon.

Hope this helps!

The Persians had THOUSANDS of soliders. Compared to the very few spartans. But btw other replier the spartans didn't just have 300 warriors that wasn't even their army because the elders said the army would not leave Sparta. But yea after the Persians took out king Leonidus Sparta fell into despair and without a king they had no tactics to defend against the mighty Persians.

You are a disgrace to all men of you have not seen 300. Sparta was a small empire with only 300 soldiers and then the Persians wanted to over run sparta they had thousands of soldiers and killed the Spartans but sparta fought like pros untill the end.

They didn't fall at the height of their power, that's semantically impossible. Sparta's main strength was ironically their main weakness- infanticide, their fascination on creating a warrior society and constant participation in wars caused their male population to dwindle over the centuries, and eventually they became drastically overstretched.