In the second half of the 8th century B.C., Sparta (Lacedaemon) conquered Messenia, a state in the southwest of the Peloponnese. The land was turned over to Spartans and the Messenians turned into helots
. The Messenians revolted in the middle of the next century, but after 17 years, the Spartans prevailed. By the time the Spartans were attacking the Arcadian city of Tegea [see Southern Greece Map
section bC], in the 6th century, her plans for the conquered citizens had changed. Tegea was made a dependent state obligated to furnish troops. Sparta soon created a confederacy of most of the other Peloponnesian states according them a similar arrangement: Sparta was in charge (hegemon
) and they would supply troops. Each had its own treaty and sent deputies to help in decision-making. This is known as the Peloponnesian League.
Argolis and Achaea were excluded from this league. Argos and Sparta had been at odds over the territory of Thyreatis (Cynuria). Their first battle proved inconclusive. The story told says that all but one on the Spartan side and two on the Argive side were killed. The Argives claimed the victory because more survived, and went back home. The Spartan stayed on the spot and therefore claimed he was the victor. The next time the two sides fought, the Argives clearly lost. However, just because they had lost the disputed territory did not mean they were ready to yield to the dominance of Sparta.
The Isthmian states of Corinth and Megara also joined the Peloponnesian League. At this time, Sparta was on friendly terms with Athens, but Athens, under Pisistratus, tried to maintain friendly terms with Argos.
Source: J.B. Bury, A History of Greece, pp. 194-5.