Wounded Sparta then embarked on a very tough, civil war equivalent- Peloponnesian war(s). But it ended it not as a former militarypower, though still strong, but as more of a political power, whichat the end of an exausting war gave them a victory. But at whatcost? Spartan system crumbled, adn with citizen populationdecimated, their army was no longer an elite, their warriorsweren’t bred from childhood to be the best in Greece, but most ofthe army were now either free semi trained periokoi (second classcitizens) or even freed helots (public slaves).
Finally, Thebans, which rose to power in Greece in 4th century BCafter almost 800 years since last heyday, defeated Spartan army inthe battle of Leuctra in 371 BC, officially ending the very slowprocess of Spartan power fading, which started almost immediatelyafter Persian wars. That wasn’t the first nor the last defeatSpartans had suffered, but it was probably the most decisive, as itnever recovered its power.
But only few decades later, Thebans also fell to the power ofAlexander the Great and Hellenistic kingdoms, who again, afterAlexander’s death soon fell to the Romans, together with entireGreece.
Sparta was slowly reduced to a remote village, a Roman touristattraction, and in the early middle ages, after several barbarianattacks and fall of Rome, it ceased to exist until refounded bymodern Greeks as Sparti in the end of 19th century where it stillstands.