Peloponnesian League

Type Object Region Peloponnese Time c. -550–-366

The Peloponnesian League was a military-political alliance of Greek city-states led by Sparta, formed in the mid-6th century BCE, playing a core role…

Timeline

c. -550–-480Peloponnesian peninsula · PeloponneseThrough conquest and diplomacy, Sparta brought Corinth, Sicyon, Megara, and other city-states into the alliance, forming the structure of the Peloponnesian League centered on mutual land defense and Spartan leadership.
c. -480–-404Greece · GreeceIn the Greco-Persian Wars the League cooperated with the Athenian-led coalition against Persia; afterwards it faced the Delian League in a long standoff, ultimately winning under Sparta and establishing dominance over mainland Greece.
-371–-366Peloponnesian peninsula · PeloponneseAfter the defeat at Leuctra, Sparta's military prestige plummeted and Thebes and other city-states challenged its leadership; after the Mantinean War of the League, the Peloponnesian League as an effective political-military organization disintegrated.

Sources

The Peloponnesian League — Encyclopaedia Britannica https://www.britannica.com/topic/Peloponnesian-League
A History of the Greek City States, ca. 700–338 B.C. — Raphael Sealey (1976)