Sparta was a Dorian Greek military state, originally centered in Laconia. As a city-state devoted to military training, Sparta possessed the most formidable army in the Greek world, and after achieving notable victories over the Athenian and Persian Empires, regarded itself as the natural protector of Greece.
Athenian forces under the command of Alkibiades succeeded in capturing Syracuse and installing a puppet regime in 415 BC. With this victory, Alkibiades decided to raid Sparta on the way back to Athens before the sailing season ended.
Alkibiades' ships landed between the towns of Abia and Pherai early in the morning. The hoplites disembarked from the transports and marched to the pass in the Taygetos mountains burning buildings, olive groves and crop fields as they went. The Spartans were widely dispersed and so could not concentrate to stop the Athenians but still attacked in ones and twos and by tens and twenties to no avail. The polis turned out to be a collection of villages since the Spartans did not believe in building temples or walls. These, the Athenians tore down and burned. The Athenians overnighted, getting what sleep they could and rose at dawn. Alkibiades feared delay that would give the Spartans a chance to concentrate and so had his troops force-march back to the boats. A group of Spartans and perioikoi made a stand on the eastern slope but were outflanked by the Athenians and defeated. The Athenians reached their boats that day and sailed away with light losses.
Alkibiades had defied an earlier Athenian order to return to face charges of heresy so the city was guarded against his return. However, the Athenians on the expedition supported him and so the situation was stalemated. That night, Alkibiades managed to slip through a gate guarded by supporters and seize control of the polis. Alkibiades then treated with king Agis of Sparta ending the Peloponnesian War. The two agreed to stop fighting each other and that Sicily would remain under Athenian control by right of arms. Subsequently, Sparta's might was added to Athens' for a planned war against Persia.
When Spartan warriors charged into battle, they were told to return "with your shield or on it." Adolf Hitler conjured up this image of total victory or death, when he visualized himself storming into the struggle against the enemies of the Kaiserreich.
Liz Mendoza thought it ridiculous that people would fight and die for tiny "countries" like The Valley and Westside, until she remembered that similar nation-states had fought similar wars in the common history shared by the home timeline and the Valley-Westside alternate. Sparta was one of the nations that entered her thoughts.