mar 1, 570 BC - *Formation of Peloponnesian League (Spartan Alliance)

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It looks as though at that point, that somebody in Sparta came up with a bright idea which changed the nature of the Spartan situation, and also introduced something new into the Greek world at the same time.
They defeated the town of Tegea, which is located just to the north of Laconia. It's a very important state for the Spartans, not just because it's the neighbor right to the north of them, but because remember what I told you, if you want to get to Mycenae from Sparta you can't go across those mountains, you got to go up north and then go left, go west into Mycenae. Tegea is right there where the road turns west. So, its strategic importance is very great. The Spartans got into this war with Tegea and they gained control of Tegea where they claimed to have discovered the bones of the great Homeric hero, Orestes and taken it away from Tegea, the bones I mean, and buried them at Sparta. Yale pg. 121 (HERODOTUS BOOK 1 PG.39 LANDMARK)

I'll go back to Tegea for a moment because that's the first case we hear and it's the model. When they defeat the Tegeans, instead of simply annexing their territory, subordinating the people, or subjecting the people to Spartan rule, they do something different. They offer the Tegeans an alliance.

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