Original members (before c.504 BC) Tegea was the first ally of Sparta in the alliance that evolved into the Peloponnesian League.Ste. Croix, Origins of the Peloponnesian War, pp. 96, 97. Corinth joined c.550.Salmon, Wealthy Corinth, p. 240. It was the most important member of the League beside Sparta. In 395, it left the League because of the Corinthian War, but returned to Sparta with the King's Peace in 387.Hansen & Nielsen (eds.), Inventory, p. 466. Its departure in 366 following the Spartan defeat against Thebes at Leuctra effectively ended the League.Ste. Croix, Origins of the Peloponnesian War, p. 97 (note 22). Sicyon remained a member without interruption until 369, when it was conquered by Epaminondas.Stylianou, Historical Commentary on Diodorus, p. 336, gives the date of 368.Hansen & Nielsen (eds.), Inventory, p. 469. Epidaurus joined because it felt threatened by Argos.Ste. Croix, Origins of the Peloponnesian War, p. 333. It remained a member without interruption until 366.Hansen & Nielsen (eds.), Inventory, pp. 606, 607. Phleius joined because of the threat from Argos. Sparta intervened into its internal politics to protect the Phleiasian oligarchs in 384 and 381. The oligarchs then remained loyal to Sparta until 366.Hansen & Nielsen (eds.), Inventory, p. 613. Halieis probably remained a member until the campaign of Epaminondas in Argolis in 369.Hansen & Nielsen (eds.), Inventory, pp. 608, 609. Megara possibly joined the League thanks to the intervention of king Cleomenes I in c.519.L. H. Jefery, "Greece before the Persian Invasion", in Boardman et al., Cambridge Ancient History, vol. IV, p. 360. Megara frequently shifted allegiances between Sparta and Athens. It might have left before 511, since an expedition of the Spartan general Anchimolius against Athens did not pass through the isthmus. It was possibly forced to rejoin by Cleomenes in c.510 when he unseated the tyrant Hippias from Athens, after which he also punished Megara by giving the island of Salamis to Athens. Megara left the League again in 461 following a border war against Corinth and joined the Delian League led by Athens, which precipitated the First Peloponnesian War.Ste. Croix, Origins of the Peloponnesian War, pp. 100, 187, 188, 212.Salmon, Wealthy Corinth, p. 262. It rejoined in 448.Ste. Croix, Origins of the Peloponnesian War, p. 123.Hansen & Nielsen (eds.), Inventory, p. 463. Megara remained in the League until its dissolution.Stylianou, Historical Commentary on Diodorus, p. 335. Aegina became member before the end of the 6th century.Ste. Croix, Origins of the Peloponnesian War, pp. 333–335. It left the League in 457 after its capture by Athens, and joined instead the Delian League.Salmon, Wealthy Corinth, p. 265. The city was destroyed by Athens in 431. Aegina was refounded by Lysander in 405 with the defeat of Athens and returned to the League.Hansen & Nielsen (eds.), Inventory, p. 621, however writes that "Subsequent Aiginetan membership in the Peloponnesian League is unlikely." Troezen left the League to Athens in 457, but rejoined following the Thirty Years' Peace. It remained loyal to Sparta until 366.Hansen & Nielsen (eds.), Inventory, p. 616. Hermione left the League to Athens c.450, but rejoined following the Thirty Years' Peace.Hansen & Nielsen (eds.), Inventory, p. 610, mention the possibility that Hermione left instead in c.425. It probably remained a member until the campaign of Epaminondas in Argolis in 369.Hansen & Nielsen (eds.), Inventory, p. 610. Elis was one of the earliest members of the League; it had already been allied with Sparta for two centuries.Wickert, Der peloponnesische Bund, pp. 13, 14.Capreedy, "A League within a League", pp. 491–493.Hansen & Nielsen (eds.), Inventory, p. 495. Like Sparta, it had many dependent cities of perioecic status.Hansen & Nielsen (eds.), Inventory, p. 490. In 420, Elis left the League because Sparta recognised the independence of perioecic Lepreon.Capreedy, "A League within a League", pp. 493–496. Sparta had to wait until the end of the Peloponnesian War to turn against Elis in the Elean War c.400. Victorious, Sparta forced Elis back into the league, as well as to release all its perioecic cities, which presumably formed two federal states and joined the Peloponnesian League.Hansen & Nielsen (eds.), Inventory, pp. 490, 542. Elis defected again in 370 after Leuctra. Mantinea defected from the League in 421, but rejoined after its defeat against Sparta in 418. It left again after Leuctra to found the Arcadian League.Hansen & Nielsen (eds.), Inventory, pp. 518, 519. Orchomenus (Arcadian) was forced to temporarily defect in 418 by the coalition of Elis, Mantinea, Argos and Athens, but rejoined after the battle of Mantinea.Hansen & Nielsen (eds.), Inventory, p. 524. The situation in the rest of Arcadia is difficult to track, with many small communities organised in tribes and leagues of their own. However, all of these communities were members of the Peloponnesian League, which they left in 370 to have founded the Arcadian League around the city of Megalopolis.
Original members (before c.504 BC) Tegea was t.he first ally of Sparta in the alliance that evolved into the Peloponnesian League.Ste. Croix, Origins of the Peloponnesian War, pp. 96, 97. Corinth joined c.550.Salmon, Wealthy Corinth, p. 240. It was the most important member of the League beside Sparta. In 395, it left the League because of the Corinthian War, but returned to Sparta with the King's Peace in 387.Hansen & Nielsen (eds.), Inventory, p. 466. Its departure in 366 following the Spartan defeat against Thebes at Leuctra effectively ended the League.Ste. Croix, Origins of the Peloponnesian War, p. 97 (note 22). Sicyon remained a member without interruption until 369, when it was conquered by Epaminondas.Stylianou, Historical Commentary on Diodorus, p. 336, gives the date of 368.Hansen & Nielsen (eds.), Inventory, p. 469. Epidaurus joined because it felt threatened by Argos.Ste. Croix, Origins of the Peloponnesian War, p. 333. It remained a member without interruption until 366.Hansen & Nielsen (eds.), Inventory, pp. 606, 607. Phleius joined because of the threat from Argos. Sparta intervened into its internal politics to protect the Phleiasian oligarchs in 384 and 381. The oligarchs then remained loyal to Sparta until 366.Hansen & Nielsen (eds.), Inventory, p. 613. Halieis probably remained a member until the campaign of Epaminondas in Argolis in 369.Hansen & Nielsen (eds.), Inventory, pp. 608, 609. Megara possibly joined the League thanks to the intervention of king Cleomenes I in c.519.L. H. Jefery, "Greece before the Persian Invasion", in Boardman et al., Cambridge Ancient History, vol. IV, p. 360. Megara frequently shifted allegiances between Sparta and Athens. It might have left before 511, since an expedition of the Spartan general Anchimolius against Athens did not pass through the isthmus. It was possibly forced to rejoin by Cleomenes in c.510 when he unseated the tyrant Hippias from Athens, after which he also punished Megara by giving the island of Salamis to Athens. Megara left the League again in 461 following a border war against Corinth and joined the Delian League led by Athens, which precipitated the First Peloponnesian War.Ste. Croix, Origins of the Peloponnesian War, pp. 100, 187, 188, 212.Salmon, Wealthy Corinth, p. 262. It rejoined in 448.Ste. Croix, Origins of the Peloponnesian War, p. 123.Hansen & Nielsen (eds.), Inventory, p. 463. Megara remained in the League until its dissolution.Stylianou, Historical Commentary on Diodorus, p. 335. Aegina became member before the end of the 6th century.Ste. Croix, Origins of the Peloponnesian War, pp. 333–335. It left the League in 457 after its capture by Athens, and joined instead the Delian League.Salmon, Wealthy Corinth, p. 265. The city was destroyed by Athens in 431. Aegina was refounded by Lysander in 405 with the defeat of Athens and returned to the League.Hansen & Nielsen (eds.), Inventory, p. 621, however writes that "Subsequent Aiginetan membership in the Peloponnesian League is unlikely." Troezen left the League to Athens in 457, but rejoined following the Thirty Years' Peace. It remained loyal to Sparta until 366.Hansen & Nielsen (eds.), Inventory, p. 616. Hermione left the League to Athens c.450, but rejoined following the Thirty Years' Peace.Hansen & Nielsen (eds.), Inventory, p. 610, mention the possibility that Hermione left instead in c425. It probably remained a member until the campaign of Epaminondas in Argolis in 369.Hansen & Nielsen (eds.), Inventory, p. 610. Elis was one of the earliest members of the League; it had already been allied with Sparta for two centuries.Wickert, Der peloponnesische Bund, pp. 13, 14.Capreedy, "A League within a League", pp. 491–493.Hansen & Nielsen (eds.), Inventory, p. 495. Like Sparta, it had many dependent cities of perioecic status.Hansen & Nielsen (eds.), Inventory, p. 490. In 420, Elis left the League because Sparta recognised the independence of perioecic Lepreon.Capreedy, "A League within a League", pp. 493–496. Sparta had to wait until the end of the Peloponnesian War to turn against Elis in the Elean War c.400. Victorious, Sparta forced Elis back into the league, as well as to release all its perioecic cities, which presumably formed two federal states and joined the Peloponnesian League.Hansen & Nielsen (eds.), Inventory, pp. 490, 542. Elis defected again in 370 after Leuctra. Mantinea defected from the League in 421, but rejoined after its defeat against Sparta in 418. It left again after Leuctra to found the Arcadian League.Hansen & Nielsen (eds.), Inventory, pp. 518, 519. Orchomenus (Arcadian) was forced to temporarily defect in 418 by the coalition of Elis, Mantinea, Argos and Athens, but rejoined after the battle of Mantinea.Hansen & Nielsen (eds.), Inventory, p. 524. The situation in the rest of Arcadia is difficult to track, with many small communities organised in tribes and leagues of their own. However, all of these communities were members of the Peloponnesian League, which they left in 370 to have founded the Arcadian League around the city of Megalopolis.