The Delian league was set up by the Athenians for an alliance between all the Ionian Greeks so to stamp out the threat of Persia. Athens took charge because Sparta retreated into its own self-interests, so to only protect themselves so the Ionians looked for help among the Athenians. It was formed in 477BC at Delos (which was a neutral city). The league seemed successful because in they had some big victories such as in: 478BC Byzantium retaken, cutting off Persians garrisons to Thrace, 475BC Eion recaptured 468BC major victory at Eurymedon River. It seemed to liberalise the Greek cities (except Sparta) and stamp out Persian threat so by 449BC there was almost no threat but in reality Athens ran the show. In 454BC the treasury moved to Athens and by 450BC most members were Athenian proving they had the majority of control of the Delian league, so what set out as a pretty democratic league became an autocracy.
The Spartans started another league called the Peloponnesian league. This was a league set up by Athens with their allies. This was a dictatorship and proud with a hatred for democracy which caused tension with the Delian league which was potentially democratic. Sparta established themselves as leaders straight away because they were the only ones who could call a meeting to do with war and they had a vote to themselves where as their allies had one vote amongst themselves and the commander-in-chief was always a Spartan general. Essentially the Peloponnesian league was defence because they had to ask for permission to wage war and have the approval from the other members of the league. The Peloponnesian league was set up against the threat of Persia. The league was very active from 554 to 500BC, it successfully stopped Aegina from trading with Persia which could be said to have more of an effect then winning a battle because not trading with Aegina affected the Persians greatly.
2. How were