The Age of Pericles
In 461 B.C. when Pericles became the leader of Athens, he moved the treasury from Delos to the acropolis. A golden age started in Athens with great cultural and artistic attainment.
** The image above shows "The Acropolis at Athens" by Leo von Klenze
Leo von Klenze [Public domain], via Wikimedia Commons
With the funds available to him, he immediately set about a rebuilding program with his two main objectives of rebuilding the temples on the acropolis and linking Athens with the port of Piraeus. Two parallel walls running from Athens to Piraeus were constructed. Though Sparta did envy the port of Piraeus, it was not seen as a threat. However, these two walls raised many questions among the Spartans, and it was believed that their purpose was of a hostile nature.
Why would Athens need these walls surrounding them? Was Athens planning another attack on Persia, which in return could lead to the Persians attacking Sparta, as they would be less protected? Or was Athens planning an attack on Sparta? After some trickery by Themistocles, who visited Sparta and a group of Spartan delegates who went to Athens, the Spartans were persuaded that the walls were in no way a threat to them.
Themistocles, who had gone to Sparta alone, told that the Spartans that unless he was allowed to go unharmed back to Athens, the Spartan delegation in Athens was to be held there until his return. Eventually the Spartans reluctantly agreed, as they needed their delegation back.
After Cimon, the son of Miltiades, became a key politician in Athens, the policy of Athens towards Sparta became less aggressive. Cimon believed that a balanced relationship would be more positive for both cities. After Themistocles being banished into isolation in 471 B.C. Cimon became the influential figure in policy towards Sparta.
Following a huge earthquake in the Peloponesse in 462 B.C. there was an uprising of the helmots against Sparta. Sparta was very fragile at this time and had to ask Athens for assistance. However, Athens was split over what to do.
One argument that was Athens should not offer help to a potential future enemy. The other side argued that helping would strengthen Greece as a whole and also be in a position to prevent a further Persian attack should it happen.
Cimon left for Sparta with about 4000 troops to show that Athens was acting under good intentions. With Pericles warning Sparta that they now had to accept the help of Athens it was taken as a huge insult that the Cimon and the troops were sent back as soon as they reached Sparta. This belief of mistrust of the Athens was shown when Sparta ended its membership of the Dfelian League in 465 B.C. Due to this insult which was felt throughout Athens, Cimon was banished in 461 B.C. The days of an aggressive towards Sparta had returned.
The Delian League, which was established to prevent against the Persian threat or attack from outsiders, had seemed to run its course in relation to its original objectives. Though the league continued to offer protection to its members, Athens started abusing the league and dominating it for its own personal gain. Athens used the league in many ways, such as economically, territorially, religiously and politically.
Eventually the members of the league came to realize what Athens was doing. Pericles claimed that as Athens and the acropolis had been destroyed in the wars with Persian, it was right that money, which was really to be used for any future problems with Persia, should be used to rebuild what they in fact destroyed.
This indeed led to friction between Athens and the other members, but as Athens had naval control over the seas, the only other alternatives were that of the Spartans and the Persians. With the promise of freeing Greece from the domination of Athens, most of Greece took the side of Sparta.