other · Greece and the Aegean

Peloponnesian League

550 BCE – 366 BCE (approx.) · capital Sparta

Sparta's network of alliances, the leading military coalition of classical Greece and Athens' opponent in the Peloponnesian War.

Origins

The league grew in the mid-6th century BCE when Sparta, after defeating Tegea around 550 BCE, turned from conquest to alliance. City by city, Peloponnesian states such as Tegea, Corinth, Elis and later Megara swore to have the same friends and enemies as the Lacedaemonians and to follow them wherever they led.

Rule and society

There was no common treasury or capital beyond Sparta. Each ally was bound to Sparta by its own treaty; from the late 6th century a congress of allies voted on war, each city having one vote, and Sparta commanded the joint army. Sparta favoured friendly oligarchies in member cities. The league formed the core of Greek resistance to Persia in 480-479 BCE.

Decline and legacy

It fought and won the Peloponnesian War against the Delian League (431-404 BCE), but the Theban victory at Leuctra in 371 BCE and invasions of Laconia broke Sparta's hold. The liberation of Messenia and separate peace deals by Corinth and others in 366-365 BCE ended the league.

Connections (13)

  • Corinth was part of Peloponnesian League550 BCE – 395 BCE
  • Megara was part of Peloponnesian League550 BCE – 366 BCE
  • Sicyon was part of Peloponnesian League550 BCE – 366 BCE
  • Elis was part of Peloponnesian League550 BCE – 420 BCE
  • Tegea was part of Peloponnesian League550 BCE – 370 BCE
  • Phlius was part of Peloponnesian League550 BCE – 366 BCE
  • Epidaurus was part of Peloponnesian League550 BCE – 366 BCE
  • Troezen was part of Peloponnesian League550 BCE – 366 BCE
  • Peloponnesian League was part of Sparta550 BCE – 366 BCE
  • Pellene was part of Peloponnesian League550 BCE – 366 BCE
  • Hermione was part of Peloponnesian League550 BCE – 366 BCE
  • Orchomenus (Arcadia) was part of Peloponnesian League550 BCE – 370 BCE
  • Mantinea was part of Peloponnesian League500 BCE – 420 BCE

More states of Greece and the Aegean →

Cite this page
APA
The Epoch Institute. (2026). Peloponnesian League. In The Epoch Institute States Register. https://the-epoch-institute.org/state/peloponnesian-league
MLA
“Peloponnesian League.” The Epoch Institute States Register, The Epoch Institute, 2026, https://the-epoch-institute.org/state/peloponnesian-league. Accessed .
Chicago
The Epoch Institute. “Peloponnesian League.” The Epoch Institute States Register. 2026. https://the-epoch-institute.org/state/peloponnesian-league.
Harvard
The Epoch Institute (2026) ‘Peloponnesian League’, The Epoch Institute States Register. Available at: https://the-epoch-institute.org/state/peloponnesian-league (Accessed: ).

Last reviewed October 2026Random state ↻