451 BCE

Athens and Sparta sign 5 Year Treaty

There were earlier troubles between the two:

    In 464, during the Hevolt revolt, the Spartans had called for help but then sent the Athenians home

    In 449, Athens allied with Spartan enemies

    In 433, the Delian League was transferred to Athens

      Both Athens and Sparta were part of Greece and wanted to hold the head of the Delian League

      Because of the move, decisions of the league were now made largely by Athens

These reasons and others suggest that the treaty was probably signed to delay the inevitable conflict