Three Treaties Between Sparta and Persia

In the first phase of the Peloponnesian War, the Archidamian War, the Spartans had been unable to achieve their aim: dissolving the Delian League. However, after the catastrophic losses that Athens had suffered during the Sicilian Expedition, the balance of power had changed and Sparta renewed the war: the Decelean or Ionian War. Moreover, the Athenians had supported a rebel in the Persian Empire, Amorges, an act that broke the (tacit or official) agreement between the Achaemenid king and the Delian League not to interfere in each other's sphere of influence. So, Sparta and Persia shared a dislike of Athens and had something to offer to each other. In 412, they concluded an agreement, which was later revised.